We see multiple RoonServer instances online that are associated with this account.
One of these machines reports authorization failures in account diagnostics - login is failing. Both of these machines report disconnections from the Roon clients to due forcible connection closures.
The logs you uploaded similarly show the network connection to the server failing - when we investigate server logs around the same time, upstream service requests to Roon’s own servers are returning generic failures.
I recommend verifying first that the Windows Defender firewall or other third-party security isn’t severing Roon’s access to the local network or loopback interface. Safelist all of Roon’s .exe processes.
Do you encounter the spinner before or after logging in via single-sign on? Is RoonServer running in the background, or has it crashed?
Lastly, we don’t see any issues with the server starting up - only the GUI. I recommend reinstalling the GUI for good measure. Create a Backup for security.