My girl friend has a Mac Book Pro 15" 2019 (i7 9880 + AMD RX 560 Pro). We upgraded from Mojave directly to Big Sure 11.0 when it was released and what a huge mistake. Since then the laptop continuously experiences these frequent crashes and reboots. None of the upgrades to 11.1, 11.2 helped. Then we did a downgrade to Mojave, after that crases appearing even more frequently. Then reinstalled Big Sur and now again on on 11.2.1. After every one to ten minutes the Mac Book is freezing and rebooting many times in a row. We tried all the tips and tricks and keyboard shortcuts found on Google, I even deleted the hard drive and reinstalled from USB Image or Internet, created a new user, nothing worked. Disk utility has dramatically changed after that downgrade, after deleting the old partitions, there are no new container or ZFS style pools created. There are only three entries under internal drive, might be a big issue? :
MacIntosh HD - Data
com.apple.os.upgrade-CE634... (Snapshot Name?)
MacIntosh HD - Data - Data
Some internet sites suggests, that after the Big Sur Upgrade, the firmware was automatically upgraded too, and now reinstalling or
Downgrading to Catalina or Mojave would not downgrade the firmware to its initial version. And that will cause lots of problems with drivers. However booting into secure mode also did nothing and the crashes persists. As MacOS is a Unix, I checked dmesg at the console after Command + S and it showed Wifi, BT and Ethernet warnings:
wlan0... Warning, invalid Wifi MAC data ...
wlan0...Warning, invalid BT MAC data ...
wlan0...Warning, invalid Ethernet MAC data ...
Luckely my girl friend has her old Windows Laptop around, so she can continuing her studies. Anybody any idea how to fix this mess? Thanks a lot.