This problem began recently after remote desktop web connection was
originally working fine.

I'll connect to the machine remotely and everything works, then I disconnect.

When I come home later that night to use the PC that is running the server,
there is no signal to the monitor, so I end up restarting the PC using the
reset button.

I've installed that latest video card adapters but no change. I'm using the
digital input from the video card to the monitor. I've tried power-cycling
the monitor, re-seating the power cable, re-seating the video cable, but
still no signal until I restart.

Could there be something in the remote desktop web settings that would
affect this?