Unable to login via Windows app (ok on web version)

That’s interesting - another user reported the same issue in our community chat with this provider.

He was able to see the following error message in the logfiles of the desktop application:

[2022-08-26 10:37:50.116] [info]  Prevented desktop from navigating to: https://framateam.org/?redirect_to=%2FXXXXXX%2F

Do you also see something like that?
If so, this specific user reported that he managed to workaround the problem by changing the URL, but I’m not sure if this would help you here:

I've put : 
https://framateam.org/?redirect_to=%2FXXXXXX%2F
Instead of :
https://framateam.org/%2FXXXXXX%2F

I hope this helps, otherwise I think it would probably help to get in touch with the framateam provider.