I have an iMac still running Catalina. I keep getting unattended kernel panic reboots with this at the head of crash report:
panic(cpu 3 caller 0xffffff7f8e7f9ad5): userspace watchdog timeout: no successful checkins from com.apple.logd in 120 seconds
service returned not alive with context : unresponsive dispatch queue(s): com.apple.firehose.drain-mem, com.apple.firehose.io-wl
service: com.apple.logd, total successful checkins since wake (5180 seconds ago): 507, last successful checkin: 120 seconds ago
service: com.apple.WindowServer, total successful checkins since wake (5180 seconds ago): 519, last successful checkin: 0 seconds ago
Kernel Extensions in backtrace:
com.apple.driver.watchdog(1.0)[B6A95892-6C75-3CF5-A6CC-6D83F30FA1D5]@0xffffff7f8e7f8000->0xffffff7f8e800fff
BSD process name corresponding to current thread: watchdogd
Any ideas?
This Stack Exchange thread looks similar. https://apple.stackexchange.com/questions/390620/macos-catalina-watchdog-timeout-kernel-panics
So I’d suggest booting in to Safe Mode before leaving your Mac alone for a while to see if the absence of 3rd party background processes causes the panics to cease. If that turns out to be the case then you’d want start doing isolation/deactivation testing of any 3rd party tools.