Incorrect visuals

Hi guys

I created a form/quiz using MS Forms. In the editor, the form looked pretty nice. Also in the preview mode, the form looked absolutely fine. Then, i checked the final URL of the form for participants. Unfortunately, there the form looked not good. Something is wrong with the visuals (see attatchments).

When i create a new form, there is the same problem. All my saved quizzes and forms have the same problem now - since this week. 

How it looks in editor and preview mode and how it should look like in live:

How it looks in live:

Where is the problem? Is there a problem with MS forms? 

Thanks for your help.

Greetz Loris