Microsoft Visual Studio 2019 can't find one script

Hi everyone,
so I just reinstalled my windows 10, so I also needed to reinstall Unity and VisualStudio (first time using 2019).

I have the problem that Visual Studio is not finding one script/class, I'm able to find all other class but only that one it underlines it red, the code is working however.

The console said sth with meta files (I erased the console before I could read it),
but I never moved the scripts manually in the explorer.
(I only copied the whole UnityProjectFolder)

Screenshot: (while "PlayAudio.cs" shows no problem, "InputBlocker.cs" is underlined)

Spoiler