PSA: Mac mini M4 auto-powers on when plugged in (Sequoia 15.7.8) — no way to disable it. Anyone else?

[Ali7]

Hey everyone,


Wanted to document this clearly since I've seen scattered reports of it but not a full explanation of what's actually going on.


The behavior: Since updating my Mac mini M4 to macOS Sequoia 15.7.8, the machine powers itself on automatically the instant it's connected to AC power — no button press, no lid to open (obviously, it's a mini), nothing. Unplug it, plug it back in, and it boots.


What I found after digging with Apple Support (multiple sessions):


This is NOT a random bug. It's the "Startup when power is connected" feature that Apple officially introduced with macOS Tahoe 26.5 to solve the infamous bottom-mounted power button complaint on the M4 mini. In Tahoe, it's a clearly visible toggle in System Settings > Energy, and you can set it to Always/Never.


The problem: this behavior has been silently rolled out into Sequoia 15.7.8 as well — but without the toggle. There is no "Startup when power is connected" option anywhere in Sequoia's Energy settings. The "Start up automatically after a power failure" setting (which HAS existed for years) is a completely separate feature and does nothing to stop this.


I spent a long time with Apple Support confirming this. They eventually admitted there's currently no fix within Sequoia and the only "solution" is upgrading to Tahoe.


Why this matters:

• This is a meaningful change in default hardware behavior, shipped silently in what should be a routine security/bugfix point release
• It's a legitimate security/safety concern for anyone with an unattended Mac mini (office, server closet, home setup) — the machine now powers on any time it loses and regains power, with zero user control
• Sequoia users are being functionally forced toward Tahoe to regain control over their own hardware's power behavior — not because of new features they want, but to fix something changed without consent

What I've done:
I filed a Feedback Assistant report (FB24122871) documenting this and requesting the toggle be backported to a Sequoia 15.7.x update. If others are affected, I'd encourage filing your own reports too — Apple tracks duplicates, and more reports on the same issue does seem to matter internally for prioritization.


Anyone else running into this on Sequoia? Curious if it's universal across all M4 minis/Studios/iMacs on 15.7.8, or if it's rolling out gradually.

 

[kitKAC]

This change would have been rolled out with the updated firmware that came with 26.6, 15.7.8 and 14.8.8. Perhaps install 26.6 into another volume and use that to switch off the auto-boot.

 

[Ali7]

This change would have been rolled out with the updated firmware that came with 26.6, 15.7.8 and 14.8.8. Perhaps install 26.6 into another volume and use that to switch off the auto-boot.

That's a really interesting theory, thank you! Quick question before I try it: once I switch it off from the Tahoe volume, does that setting persist at the firmware/hardware level even after I boot back into Sequoia, or does it only apply while actively running Tahoe? Also, does this require erasing anything, or can Tahoe be installed as a separate APFS volume alongside Sequoia without affecting my existing data?

 

[kitKAC]

It should be persistent; the firmware is loaded before macOS is. No need to erase anything! Just create an APFS container alongside Sequoia and stick Tahoe in there.

 

[Bigwaff]

The problem: this behavior has been silently rolled out into Sequoia 15.7.8 as well — but without the toggle. There is no "Startup when power is connected" option anywhere in Sequoia's Energy settings. The "Start up automatically after a power failure" setting (which HAS existed for years) is a completely separate feature and does nothing to stop this.

If you run man pmset, is one of the settings autorestartatconnect ? If so, to turn off automatic restart on power connect, try the following command with root privileges:
sudo /usr/bin/pmset autorestartatconnect 0

 

[Ali7]

If you run man pmset, is one of the settings autorestartatconnect ? If so, to turn off automatic restart on power connect, try the following command with root privileges:
sudo /usr/bin/pmset autorestartatconnect 0

Thanks for the suggestion! I actually found this documented too, but interestingly, other users on Sequoia 15.7.7 reported that autorestartatconnect doesn't even show up when running pmset -g on their systems, and setting it manually didn't change the behavior at all — someone speculated it might need to be set via NVRAM instead, but that wasn't confirmed either.

In my case, I ended up solving it by installing Tahoe 26.6 on a separate APFS volume, toggling the setting off from there (via System Settings > Energy), then switching back to Sequoia — the setting persisted since it's firmware-level. That approach worked reliably for me. But if pmset works for others on Sequoia, that'd be a much simpler fix — worth documenting here for others to try.

 

[benholt]

For anyone who doesn't want to burn a whole APFS volume on this: a bootable Tahoe USB installer is enough. Boot with the power button held (Apple Silicon holds power for startup options), pick the installer, get into System Settings > Energy from the installer environment, flip the toggle off, then reboot straight back into Sequoia. The setting sticks because it's stored at the firmware/sep level rather than in the OS. Takes maybe 15 minutes and the USB is disposable after.

One wrinkle: an M4 mini needs a Tahoe 26.5-or-later installer since earlier builds don't include the Energy toggle UI. From any current Mac you can grab it with softwareupdate --fetch-full-installer --full-installer-version 26.6, then createinstallmedia the usual way onto an 16GB+ USB. Faster than baby-sitting a second APFS container long-term, and doesn't leave anything on the mini itself.

 

[Fishrrman]

OP wrote:
"I filed a Feedback Assistant report (FB24122871) documenting this and requesting the toggle be backported to a Sequoia 15.7.x update"

Here's a "Fishrrman fearless 100% gold-plated" prediction:
That isn't going to happen. Ever.

You CAN turn this off if you wish, but it has to be done while running either Tahoe or GoldenGate.

It surprised me at first, but I've come to PREFER the way this works.

I keep the Mini and all connected peripherals plugged into a surge supressor/power strip.
At night, I shut down the Mini, then reach down and flip OFF the power strip.
That way, everything is "removed from the mains" overnight. Old house, old wiring.

In the morning, it's a "one-button start" -- I reach down and flip the power switch on, and the Mini and everything else comes right up, waiting for my login.

(you've already found the workaround, but I'll reiterate):
If you don't want to "upgrade" the internal SSD beyond Sequoia, do this:
- Find an external SSD -- even one as small as 128gb will work.
- Install Tahoe or GG onto that
- Boot from the external SSD, change the setting, boot back to Sequoia.
- Done.

 

[bzgnyc2]

Is this new setting perhaps stored in the NVRAM? For those of you who have already applied the fix, can you share the results of running in the Terminal:

nvram -p

or for those on Tahoe 26.5+, show a diff of nvram -p with and without the change in settings? If an easy NVRAM setting, others could restore the previous behavior without having to download and create a Tahoe boot disk.

Spoiler: Completely unrelated observation

Apple updates the firmware far too often and is far too cavalier about rolling functional changes into any firmware update

 

[MacCheetah3]

Is this new setting perhaps stored in the NVRAM? For those of you who have already applied the fix, can you share the results of running in the Terminal:

nvram -p

or for those on Tahoe 26.5+, show a diff of nvram -p with and without the change in settings? If an easy NVRAM setting, others could restore the previous behavior without evening have to download and create a Tahoe boot disk.

List of parameters (as of macOS 26.6):

BluetoothInfo
boot-breadcrumbs
supervised
prev-lang:kbd
IDInstallerDataV2
LocationServicesEnabled
boot-volume
lts-persistance
upgrade-boot-volume
skip-language-setup
SystemAudioVolumeExtension
bluetoothExternalDongleFailed
wlancprops
panicmedic-auxkc-present
auto-boot
BluetoothUHEDevices
ota-updateType
display-crossbar0
bootdelay
SystemAudioVolume
usbc,version,rid0
panicmedic-timestamps
bluetoothInternalControllerInfo

By the way, for anyone curious/wondering, auto-boot is true no matter what the Energy setting, including when set to Never.

 

[bzgnyc2]

List of parameters (as of macOS 26.6):

BluetoothInfo
boot-breadcrumbs
supervised
prev-lang:kbd
IDInstallerDataV2
LocationServicesEnabled
boot-volume
lts-persistance
upgrade-boot-volume
skip-language-setup
SystemAudioVolumeExtension
bluetoothExternalDongleFailed
wlancprops
panicmedic-auxkc-present
auto-boot
BluetoothUHEDevices
ota-updateType
display-crossbar0
bootdelay
SystemAudioVolume
usbc,version,rid0
panicmedic-timestamps
bluetoothInternalControllerInfo

By the way, for anyone curious/wondering, auto-boot is true no matter what the Energy setting, including when set to Never.

Thanks MacCheetah3 for sharing. I assume you deleted the actual values and just showing the potential variables? Also I assume this is after "Startup when power is connected"="Never" is set via System Settings > Energy?

If so, the only one that I would look at further is "bootdelay" -- does it take different values when "Startup when power is connected" is set to "Never" versus "Always"? Otherwise, I am guessing the decision is hidden as a binary/hex flag in one of the other variables or written to some invisible part of the Mac's power supply.

 

[MacCheetah3]

I assume you deleted the actual values and just showing the potential variables?

Correct.

Also I assume this is after "Startup when power is connected"="Never" is set via System Settings > Energy?

Yes.

If so, the only one that I would look at further is "bootdelay" -- does it take different values when "Startup when power is connected" is set to "Never" versus "Always"?

Interesting guess. Unfortunately, that value doesn’t appear to change either. Boot delay stays set to zero on all three options.

FYI… I did a shut down (not restart) after each changing of the setting, waiting more than a minute before the next power on (i.e., power button press).

P.S. I mentally noted some of the boot-breadcrumbs string, because I have no idea what it really is, and didn’t notice any of the hexadecimal numbers differing after the setting change as well.

 

[bzgnyc2]

If so, the only one that I would look at further is "bootdelay" -- does it take different values when "Startup when power is connected" is set to "Never" versus "Always"?

Interesting guess. Unfortunately, that value doesn’t appear to change either. Boot delay stays set to zero on all three options.

FYI… I did a shut down (not restart) after each changing of the setting, waiting more than a minute before the next power on (i.e., power button press).

P.S. I mentally noted some of the boot-breadcrumbs string, because I have no idea what it really is, and didn’t notice any of the hexadecimal numbers differing after the setting change as well.

Unfortunate we didn't find a magic NVRAM variable or what to control this but I think was worth a look and thanks for looking into that for everyone. For now, the boot off an external Tahoe installer disk to access its System Settings solution probably the most accessible solution for most.

 

[skn]

For anyone who doesn't want to burn a whole APFS volume on this: a bootable Tahoe USB installer is enough. Boot with the power button held (Apple Silicon holds power for startup options), pick the installer, get into System Settings > Energy from the installer environment, flip the toggle off, then reboot straight back into Sequoia. The setting sticks because it's stored at the firmware/sep level rather than in the OS. Takes maybe 15 minutes and the USB is disposable after.

One wrinkle: an M4 mini needs a Tahoe 26.5-or-later installer since earlier builds don't include the Energy toggle UI. From any current Mac you can grab it with softwareupdate --fetch-full-installer --full-installer-version 26.6, then createinstallmedia the usual way onto an 16GB+ USB. Faster than baby-sitting a second APFS container long-term, and doesn't leave anything on the mini itself.

I tried your suggestion but there is no such option (System Settings > Energy) from the Tahoe 26.6 installer environment on a Mac mini M4, unfortunately. Thank you!