I just started this round. When I first attempted to log in I had to use Google translate to get on. I was given a box that wanted my activation code, however even though I had already chosen English-US, the box was entirely in German (which I don't read). I was able to get past that box only by copying the language to translate, and then finding out what it wanted. Once I entered the activation code, a new activation code popped up in German again. I had to restart the game to get past that box, as it would not accept my activation code. Once I restarted the game, everything was in English, and language has not been an issue again.
Hei Dr Steam
at first, welcome to our PTR Servers and forum
that sounds a little weird.
Did you perhaps accidentally set the Rail Nation website that you used to register at PTR to German before?
No, All started in English and once I got past that screen everything was in English again.