Got the same problem. Two days in a row now.
Only solution is to hard reset the server.
Same upgrade path v6.9.2 to 6.10.2 (6.9.2 -> 6.10.0 -> 6.10.1 -> 6.10.2)
Server was online for weeks on 6.9.2 with no problem.
Problems came with the upgrade to 6.10.0, first after a few days, now on 6.10.2 every day.
I'll enable the syslog server as well and will post the logs here, the problem will happen soon enough again.
edit. as an added note as I'm using IMPI to check on the server, there is no remote response, no CLI, no gui, nothing. So it's probably not a network thing. The system seems to freeze with no interaction possible.
edit2. I attached a previous log with the problem happening at the 23:07:00 mark (lost connectivity at 23:08:44).
syslog-unraid-02june2022-23-08-44.txt