I enrolled at fh Aachen yesterday and today I received the message that my application was rejected?

So, I applied to two universities through Hochschulstart (Stuttgart and Bremen). I was ranked poorly in Bremen, and I could have enrolled directly in Stuttgart.

But now I wanted to go to Aachen, so I applied there through the Aachen portal. Everything worked out, and it also said I could enroll directly. However, my application wasn't displayed on Hochschulstart!

Well, I enrolled at Aachen yesterday. Today I received a message via the Aachen portal saying it was rejected. Huh? The statement says it was rejected (the coordination phase of the DOSV has expired or something).

Hey, what's going on here? I'm already feeling really disappointed, aggressive, etc. because of this unnecessarily complicated crap in the German application process. But this is the limit.

How can it be that I accept an offer and submit my application for enrollment there, only to be rejected because the coordination phase has expired? I couldn't have even prioritized the Aachen application or anything because it wasn't displayed on Hochschulstart.

I will of course call there tomorrow but please also ask for help/answer here.

By the way, thank God I was at least accepted in Stuttgart and am now supposed to enroll there.

So the question is, why would I be rejected in Aachen?

Thank you very much

P.S.: I'm slowly losing faith in humanity, or in myself. I'm not actually disabled, but I'm starting to feel that way. Although, judging by the questions I ask online, I can tell that no one understands.