This also started appearing on a Mac mini 2018 that is being used as a fileserver. It might coincide with the upgrade to macOS 11.6 or 11.6.1. Every few weeks to just days I find the machine had restarted with the all too familiar crash report:
userspace watchdog timeout: no successful checkins from com.apple.remoted in 180 seconds
[...]
There were no such issues with 10.15; connected peripherals have not changed.