Yup

Thanks. It was due to me using a wrong port. Its working now.

Sorry for the inconvinience

Yes, also occures without the header. But I think I know the problem now: I tried to use the certificate of my host provider, which seems not to work for federation

Ok, yeah, I’m using a certiciate of my domain provider. Maybe that’s the problem … thanks! I will try to do it with letsencrypt/acme

Or do you know a similar post maybe?