Here's something I've noticed recently - the Windows 10 Start Menu is hosed, exhibiting the same thing you mention, you can see the icons, but they are unclickable.
Turns out that for us, UEM is the culprit. I was able to solve this by DISABLING the Windows Explorer setting in UEM. Yes: UEM default config is somehow gakking Windows 10 start menu - by default. So, by default, I now pretty much disable most of the user environment stuff in UEM and stick to ADMX template method of customizations.