Upgraded to Catalina and now I have 16 inviisble Spaces

I upraded fom High Sierra to Catalina and a few things like shortcuts for individual spaces were not working correctly.

I had 9 Spaces, then I upgraded TS to 2.9.9 and now I have 16(!) spaces, but none is visible/accessible! In the Preferences it looks like this:

How can I fix this? Maybe blowing away all prefernces? How do i do this?