VNC Server on macOS listens for about a day, then stops listening

I have a 2021 MacBook Pro laptop (M1 CPU) and I'm running the latest version of VNC server.  It generally works fine, unless I don't touch the laptop for an entire day.  I always leave my user logged in and just close the lid.  After closing the lid, VNC server still listens and I can connect.  Even if I let it sit there for 16 hours, VNC server still works and I can still connect.  However, if I don't touch the laptop for about 24 hours or more, suddenly VNC server is no longer listening and I can't connect.  I haven't measure exactly how long it takes for VNC to stop listening, but it's roughly 24 hours and it's very consistent.

After VNC stops listening, I can make it listen again by simply opening the lid.  No need to touch any keys or do anything.  After opening the lid, I can see that my user is still logged in.  I can see that the laptop did not go to sleep because the desktop is showing instantly.  Also, I can ping the laptop's IP address from another computer, so I know the laptop was up and running before I opened the lid.  It is only VNC server that has stopped listening.

Obviously I've checked the laptop's sleep settings, etc.  Everything is set to never sleep, never lock the screen, never require a password, etc., etc. The whole reason for having VNC server is so that the computer can be accessed remotely, so having someone "lift the lid" on the laptop to get VNC server to listen again is no good.

Any suggestions on how to troubleshoot this?  Thank you for any help you can offer.