MacBook Pro will always reboot after shut down

[Philebos]

Hello,

I have a problem with my Macbook Pro (late 2013) and I just cannot find
the cause. After selecting “shut down” from the apple menu it will
always reboot after 10-20 seconds. The same happens after a “hard shut
down” (holding the power button). It also reboots when shutting it down
from buit-in macOS Recovery system.

I have made videos to illustrate the problem:

The only way to shut it down is a “hard shut down” while the battery
charger is disconnected (if the charger is connected it will reboot).
Apart from this the Macbook works perfectly fine.

I have tried several things I found on the Internet.
-NVRAM and SMC were reset
-Apple diagnostics was run
-I checked the hard drive with “disk utility”
-I ran various diagnostic apps (“EtreCheckPro” for example)
-To exclude all software problems I totally wiped the hard drive and reinstalled macOS

Has anyone an idea what might cause this?

thank you very much in advance for any help!

 

[ssls6]

My mid-2014 also reboots after a shutdown but that seems to take a few minutes. I think it's a bug in Big Sur when the device is left with charger plugged in.

 

[IHelpId10t5]

This symptom started on my 2013 MBA after installing replacement battery and SSD from OWC. The MBA has worked great after the upgrades other than the extra reboots. Another time when the sudden reboot occurs is if it is unplugged from power while closed and sleeping. That causes an instant chime/reboot despite being closed. I have nothing but good things to say about OWC upgrade parts but the reboot issue absolutely started just after my upgrades.

Do you happen to have replaced parts in your MBA?