Base socket connection to HSQLDB server closes after long idle time

Version: (x64)

I have a Base application that works fine connecting to an external HSQLDB server. I have noticed that if application left overnight, at some point the socket connected to server process closes. Closing LibreOffice is necessary to restart the application. I have looked through the LO options, and checked the HSQLDB documentation, but cannot find any setting for socket lifetime. Anyone know if this can be controlled?

Worst case, I guess I can run a scheduled task to kill both the app and database overnight, forcing users to start fresh every day.