Myopenhab login impossible

I registered a new openhab server in my new myopenhab cloud account.

For this admin login I used a mail address like ‘name+openhab@gmail.com’. The registration was successful and I could verify my account and already add a new regular user.
But if I try to login with my credentials again I only get the error message ‘Unknown user or incorrect password’.
The regular user still works fine (which has no ‘+’ in the mail address) but my admin user is kind of lost.

Is there a way to login again with my admin user or change the mail address in the system?

Can’t point you in a specific forum post, but can say this. There is a bug and + in an emails does not work. Need a new email, sorry.

Yes, it doesn’t work.
I locked myself out of my account by using a + in my email address, had to make a new account.

Someone fortunately raised an issue on GitHub so maybe this is eventually getting fixed in the future.