It seems to be fixed now, it hasn't crashed in 3 days. And the thing i did was to change from plexinc/pms-docker to lscr.io/linuxserver/plex and now it seems all good.
So my server keep crashing, up to day it died once a day and sometime it rebooted. Now it dies once an hour it feels like.
Before this problem it the server ran fore almost 2 months. Before i updated the server and restarted it.
ubbe2-diagnostics-20230816-2119.zip
syslog-192.168.2.206.log