This may be a long-shot, but after the upgrade to 22 from 21 when I powered down the opnsense system (pressing the power down button), it rebooted.This was reproducible, and there was no apparent reason why this would occur.I then reset the bios.The reboot issue has gone (fingers crossed!!)This issue did not occur with 21, so I wonder if 22 modifies the bios in some way?