I had this issue on a 13 inch pro T2 security drive that I erased to protect my drive from hackers in my system. I erased the start up disk by a mistake but I think it was just basic instinct. I went into the /private/var/db folder after a google search and there is a folder called mds inside was install.lock or something like that and another one. I removed that. Also I went into each folder including temp and removed mobileactivationd that is a very malicious file that could give anyone access to your system bypassing apples servers. My guess is it was introduced on a usb or even through a hub. I use Baseus no issues but I used to have a random restart at 2 mins remaining and 3 minutes remaining had to calm down cause it’s really exhausting when your up all night trying to solve an issue and you have to go to bed without it being solved. I pulled the hub at 4 mins remaining and no restart and as I suspected with the deleted files of course with a google search to confirm it’s functionality I removed some residual windows files that were also buried in the drive I went through every file and folder possible . I did another google search and figured out that There might also be AppleSetup.done as well in the db folder remove that file as well it tricks your system into thinking your all done but the system can’t find those files so panics. I’d like to thank the kind apple technicians I spoke to at first that calmed me down and just gave me a direction and I ran with it 2 mins to go is taking a bit but tomorrow I’ll wake up it’s my studio lol so priority attention. I didn’t sleep last night but feels good to know why. I can see the function where they even killed the internet as it counted down sheer wickedness but Grateful.