Suddenly i get a Vodafone 691 fehler page

Hello,

here is Kundennummer DE16714086

A couple of weeks ago, from one moment to the other my internet connection went off. I tried multiple time to successfully factory reset the o2 box. In the o2 box GUI, and according to the lights on the actual box everything seems working correctly. But as soon as I try to connect to internet I get a Vodafone 691 error page (see attachment)

I did not just move in, internet was working correctly for months. I did all the possible steps that were available to fix the issues, now I don't know what else to do. The customer service on fb stopped answering me.

I was reading around the o2 community and apparently problems like this need the intervention of a technician, could you please arrange one. How would this work?

Thank you in advance for your help.