I’ve experienced frequent reboots on my RB333 with ROS 3.0rc10. It has rarely run for more than some hours or at most a day before rebooting without any reason.
From another post I was recommended to disable the watchdog. I did, and now it looks like the router is more stable already, it has already run for 60 hours! Celebrate! 
Can anybody please explain how this watchdog works and at which events it is supposed to reboot the router?
I know there is a feature for pinging a specific host and rebooting after a certain timespan without response, but initially I never filled in the address field, just left the “watchdog timer” checkbox checked, as it is by default. This resulted in reboots every now and then.
Then I unchecked the “watchdog timer” checkbox and everything seems to be fine, at least so far.
Is this different between RB models and between 2.9 and 3.0? I have an RB112 with 2.9.40 that has run for months without any reboot.