Anki sometimes fails to reveal the cloze tags

I am using the most recent vrsion of Anki on Windows. Worked perfectly well for a while but now I occasionally get this bug:

I get a cloze card -> Cloze tags are “active”, show the three dots and marked blue -> I press space to reveal the answer -> Cloze tags still show the three dots and no answer is revealed. The easy/good/hard/again buttons show up.

This does not happen on ankiweb or inside the iOS app with the same cards. Card preview via browse works, too. I did all the database cleanups the tools menue provides. I updated from 2.1.34 to 2.1.35 but the issue still persists. I rebooted the computer (just in case) but it didn’t help.

Any idea how to fix this?

Changing your video driver may help: