PROBLEM SOLVED
I just had my “d’oh” moment & feel like Homer Simpson … I really should have thought of that.
Entering the account-number manually solves all problems
God, Mulvad is fast compared to OpenVPN … BUT:
Mullvad does not let me stream TV-Content from country A, when travelling in country B … same as Netflix: just doesn’t work through Mullvad/Wireguard…
but this is a Mullvad issue, no gl.Inet one. Those routers just rock.
Thanks everybody for their help 