I’m running since more than 1,5 years now OH.
Current on a PI 3B+ mit 16GB MicroSD Card, and arround 25 devices connected and on latest OH version 2.5-9
From time to time ~2 weeks I have the issue, that the OH stops working. The serice is not more answering, the WEB UI’s are not more reachable. I can still login in the PI per Telnet.
After reboot the system is coming up, has now all the devices found as NEW devices.
When I stop the service, restore the saved backup, amke make a reboot, the system is up and running again for the next ~ two weeks.
Power supply is just a guess, easy to try another if you had one. The issue would be if the power supply goes to a low voltage it may cause a read write error to the sd card. Or the pi May reboot on its own.