Hi Jan,
I and some other users have been wrestling with random crashes and restarts of the Roon Server process on Ubuntu Desktop, which seems to be related with NetworkManager and the dhcp4 client calling to its server. One thing you can do to ascertain if you are experiencing similar issues is to look for SIGSEGV events in your syslog archives. You can do that by
grep SIGSEGV /var/log/syslog
and
grep SIGSEGV /var/log/syslog.1
For the compressed syslog archives (syslog.2.gz etc.) use zgrep instead of grep.
If you find SIGSEGV events related to Roon server processes I’d think we could be fairly sure you’re experiencing the same problem I and others (e.g. @Robem) have had.
In this case, the first thing I’d do is to configure the IP of your Roon Core server with a static IP. If the IP is static, there won’t be any more dhcp4 calls to renew the IP lease from its server, and this for me has ultimately been sufficient to solve the problem. If you do this, remember to configure the IP address reservation on your router to avoid future address conflicts with other devices on your network.