Only the first link shows how to enable Screensaver.
The rest of the tutorials show how to fix screensaver when it is not working correctly, which is exactly your problem.
Please read past the first link before rejecting the fixes which work most for screensaver I have been giving for years here.
The please report back results of the repairs so I will know what else to suggest. Please don't skip any steps. We often find out later that the fix was the skipped step. If you need help performing any step I will help.
Since you know when this was started, you can also System Restore to a point before the problem started:
https://itechhacks.com/system-restore-windows-11/
System Restore is your first line of defense and can take you back to a point before a problem began like a time machine. If it doesn't help then you can undo it. Read about it first in the tutorial above and then try restoring to just before this started. If System Restore is not enabled on C drive do that now so it's available in the future.
If the problem repeats or System Restore doesn't work then check which Windows Updates were installed at Settings > Update & Security > Windows Updates > Update History, uninstall them there or System Restore again, then immediately check for and block the Updates with the Hide Updates tool explained here:
https://www.droidwin.com/how-to-stop-only-a-spe...
Feel free to ask back any questions. Based on the results you post back, I will have other suggestions if necessary.
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