Strange Creative Cloud Login Loop (Enterprise/School)

Im in the process of installing the Creative Cloud App for my girlfriend on her laptop, but I am caught in a weird log-in loop.

The laptop has a fresh Windows 10 install on it. I activated the system Admin-Account and have full access on this PC. Their school uses Adobe Okta and if I try to log in with Firefox it gives me an error, that the school's certificate (idp.graphische.net) isn't valid. I solved that with an exception.

However, if I download the creative cloud installer and try to log in, I get a weird prompt, that is a "windows security" window and doesn't seem to belog to the creative-cloud program. I attached my dxdiag and the creative cloud log in loop. If anybody has got an idea, especially if its my fault or the Okta at the school, please let me know.

Regards,

Ari