If I wake up the computer after putting it to sleep, most icons (except those in the search result), text, background images are gone and the screen is almost black. Even the menu text is gone, so I could not log out, other than typing logout, pressing enter and then choose between two black buttons (at first try, I clicked the left one, but that was cancel).
Other than “Don’t use Wayland with Nvidia”, is there any solution for this?
Don’t use a broken custom theme? 
What is exactly is a “custom theme”? I don’t think I had installed any new theme. All I had down was selecting something in the drop-down list in the Tweaks.
If there is any misunderstanding, it happens only after waking from sleep; initially they look fine.
A Gtk or GNOME Shell theme created by a third party installed by you. That does not seem to be the case here after all.
Can you reproduce the issue with extensions disabled or creating a new user account?
