Solved, at least I think so...
It took some digging but I finally found a setting that fixes the problem. In the event that someone else runs into this I'll give a better explanation of the problem and the setting that fixed it. I have no idea what in the update caused the change of behavior.
(and a thanks to Zybex for the suggestion, but the computer sleeping wasn't the problem)
I have an HTPC which primarily runs JRiver for music/Movies, the usual.
This system when booted auto logs in a user account and starts MC. It is left in this state whether being used or not and eventually will go to sleep. This setup has worked well for a number of years.
What the update changed was that the user login was shutdown due to inactivity which of course meant that MC was no longer running.
The fix involves changing a setting in security policy. Run SECPOL (local security policy) and navigate to the following:
Local Policies
Security Options
Interactive logon:Machine inactivity limit
This is probably set to "Not Defined", change it to be 0 seconds and the system will no longer kill the user logon.
Thanks to everyone for their help.
PS: I run Win 11 Pro on this system so I don't know if you can run SECPOL directly on a Home system or not.