Bluetooth issues after installing Security Update 2019-001 (High Sierra)

mj_

macrumors 6502a
Original poster
May 18, 2017
572
290
Austin, TX
I've been experiencing some Bluetooth issues after installing yesterday's Security Update 2019-001 on High Sierra. Coincidentally the same ones that made me downgrade from 10.14 back to 10.13 a while ago.

This morning, when I woke up my 2017 5K iMac from sleep, all Bluetooth devices (Apple Magic keyboard, Logitech MX Master 2S mouse, Jabra PRO 9470 headset) were disconnected. I was unable to enter my password or move the mouse cursor and had to plugin a USB keyboard and mouse in order to login, disable Bluetooth from the menubar, re-enable it again, and reconnect my devices.

Ever since, the mouse cursor has been stuttering massively when moved across the screen, and it gets worse if another Bluetooth device such as my headset is in active use at the same time. What I have not yet experienced are the connectivity issues with my headset, so far that seems to be working well.

According to the release notes for said security update Apple fixed a few Bluetooth bugs in 10.14 and 10.13. I'm afraid that they might have backported the Bluetooth stack from 10.14 to 10.13 in order to streamline their bugfixing process for the future. All of my devices worked flawlessly with 10.13 until yesterday, and now all of a sudden they are acting up. This can't be a coincidence.

Did anyone else make similar observations with Bluetooth devices after installing the latest security update?
 

Ruskes

macrumors regular
Jan 4, 2019
135
37
On my 2017 MBA with High Sierra 10.13.6 all is fine with BT.
There is no update available at this time.
You are right to assume it might be a problem with your Downgrade from 10.14 to 10.13
Not shure if I understand, but did you use the BT Reset ?
Hold Shift+Option and click on BT icon in the top bar
Use Debug...
 

mj_

macrumors 6502a
Original poster
May 18, 2017
572
290
Austin, TX
All is fine with BT on my MacBook as well. And all was fine with BT on my MacBook back when it was still running 10.14, too. It's only the iMac that is affected, and the issues are definitely not due to the downgrade because downgrading from 10.14. to 10.13 is nothing less than completely wiping the hard drive, reformatting it from APFS to HFS+, then performing a clean install with manual restoration of all my files because Time Machine is unable restore files from a backup of an operating system newer than the one installed (aka: I was unable to use the Migration Assistant to restore files from my latest 10.14 backup to 10.13 but had to do it by hand). That may be because of Apple's innate "newer is always better. why? because it's newer. duh." attitude that I hate so dearly.

Long story short: it is definitely not a downgrade issue. And Bluetooth was working just fine on High Sierra for weeks until I installed the 2019-001 security update yesterday afternoon.
 

mj_

macrumors 6502a
Original poster
May 18, 2017
572
290
Austin, TX
Well, Apple has definitely messed with High Sierra's Bluetooth stack. This morning I found my Bluetooth headset disconnected while both keyboard and mouse were still connected. I've had to manually reconnect the headset. Also, I've just discovered that the mouse pointer freezes for about a second or two when I open and close (!) the Bluetooth Preferences in System Settings. It's completely unresponsive, and will then jump across the screen to catch up.
 

BugeyeSTI

macrumors 68030
Aug 19, 2017
2,862
1,932
Arizona
Just to give you some feedback, I haven’t had any Bluetooth issues on my iMac after the 2019-001 update...