If I try from my FP6+, the Login cannot be completed (it tells me I should check my internet connection, which is obviously working, since I did the rest).
As a counter-check, I tried to login into the browser (instead of the app) and that works fine.
As an additional information: also the Payback (to get points when purchasing something in supermarkets) and Easypark (to park in Berlin) are giving me issues with the login.
So maybe there is some setting/configuration/missing service which is giving me issues…?
I suspect something with google, but cannot really understand what, at the moment.