Registration issue on Mein o2: SMS security code contains only a dot instead of numbers

Is that some o2 issue or is there something wrong with my SIM/phones?

There is a problem with o2 that can only be resolved by the technical department. Since you are registered here only as a prospective customer, please contact the English-speaking hotline.

​@Almahid1 I found a small trick:

I had that same error over the weekend!

But I found a trick to get the code anyway:

Go to the login page, enter your email address, click "Continue," then select "Log in without a password," enter your mobile number, and you'll receive a code.

I pasted my answer from another thread and used a translator due to time issues. 

Please give feedback if these steps work for you.

Hi,
​@5G_Tester yeah that helped but… that let me only login to my “account” but doesn’t let me create login/password. 

​@Bumer I have called support department and they couldn’t solve anything. They have just told me to wait 24h and try again - I’ve waited over 36, still same issue - SMS with just a dot, without OTP/code.


Edit:
I managed to do the following(kind of fixed my issue)
Forgot my password → used my number as “Nutzername” → set a new password(which I had never set before xD) → now I can log in with my number/password, but still not with Nutzername/e-mail. Also, there was a message that I will receive password change confirmation by e-mail - I didn’t :P 

Isn’t it a bit insecure that I could “reset/change” my password just by having phone number and nothing else like user name or email?

Registration should always be done using your phone number as your username. Glad it's working now. You don't need to worry.