iMac Restarts during Sleep

My late 2020 Intel iMac running Ventura 13.2.1 has been restarting after it sleeps. If I leave the iMac unused this happens before the time I specify in System Settings for screen saver and turning off displays. I come back from a short break to find all the applications closed and the Lock Screen displayed (with both User and Test log ins).

I have reset SMC and started in Safe Mode but neither has helped. In the crash report section of Console there are two reports referencing "TextInputSwitcher" and "DTOCRHelper" (Devonthink) but I cannot interpret the reports to understand what happened.

Otherwise, the iMac is running almost perfectly. "Find my...." is not working for other devices despite being set up correctly, but I do not think these issues should be related.

Providing I do not leave it for any length of time my iMac works well. It is just frustrating having to log in and restart all apps for no obvious reason.

Can anyone suggest a cause and solution?