Like I said in the title, the Google Webmaster Console claims not to find the robots.txt file of my homepage and therefore it won't crawl it.

But there is a robots.txt file (<https://soundhaus-band.de/robots.txt>). 
And Google can read the correct content of the robots.txt in the robots-tester.

I also tried to fetch the robots.txt as Google and then add it to the index. But this does not help either.

Can anyone help me?