Hey all,
Just a heads up - I ran 'apt upgrade' today and there were some new kernel updates - 5.15.75. Both my RockPi 4B's failed to boot after applying these updates.
Booting off an SD card, and copying the kernel components of 5.15.63 from /boot of the SD card to /boot of the EMMC, and removing the 5.15.75 components got me back up and running.
Cheers
Paul