I have a very similar issue... was running 1903 update and everything was ok.. then updated to 2004 which completely broke all of my network drives.. then downgraded back top 1903 and now screen saver not working.. Microsoft.. please please please test your updates properly... I rely on Windows 10 for my business and I can not simply have it stop working because you have not done complete testing.
I have now have no idea how to fix the screen saver issue.. it just doesn't work period.. and NOTHING has been changed on my part.. except the upgrade to 2004 and then the downgrade to 1903 so clearly they two are related.
I have looked at all of the suggestions to date and none of them have resolved the issue.. screensaver simply doesn't kick in..
Thoughts/comments?
P.
Happened with me too. Previously I went to Level 3 support and it turns out that the bug is due to to synching settings. with the latest 'upgrade' this was enabled and so my screensaver has gone. Even if you untick synch- too late! The only way to fix it, is to add a new local account; move across your files; reinstall all your apps; add in your MS account; etc. Grrrrrrr