Email or passwored change (gcm: tag doesn’t match)

Well,

system doen’t work for me:


This is where I get. clicking on submit doesn’t do anything. The submit button turns gray for a few seconds, thats it. Turns back blue, no response.


This is, what I get when trying to login with the new mail and old password.


This happens, when I try to reset the pw for the new mail.

And last but not least:


I can’t initiate the mailchange again, as it states the mailaddress is already taken.

And for the love of god I even tried using microsoft edge, still -same unpleasent result.

Any ideas on this?