I have not had the screensaver working problems for a couple of years with Windows 10. Just occasionally it would work for a day or so after an upgrade and then stop.
I unplugged all the USB devices - Logitech camera, MS joystick and CH Pro pedals (for flight sim). This did not work, however I was running nVidia GeForce Experience and selected IN-GAME OVERLAY OFF and the screensaver and power saving started working again reliably.
Since then I have had to start using Edge rather than IE 11 as MS Teams required it. When Edge is running it prevents the screensaver working. A full reboot will reset the system and it works again. This problem does not occur with IE 11. It seem Edge is preventing screensaver or power saving working.
Richard,
Thanks, I tried many other solutions and this one worked. It was my usb game controller attached to a hub that was causing the hangup.
Same. Screensaver has kicked in fine forever. Late last week for some reason, it just took it upon itself to stop. Tried 'On resume, display logon screen' but it did nothing. Sure enough, I unplugged my Xbox controller that I use on a daily basis, and it began working again. I'm sure when I plug it back in, it'll stop again.