Thanks pato for joining the discussion.
Perhaps of interest: After moving to the existing address in 2018, I asked the landlord to seal the TV plug in the apartment, as I didn’t need additional costs (I was with the swisscom). EBL, as the service provider, confirmed a little later that it had “sealed” the TV plug remotely. I was therefore able to install the equipment without problems a few days ago, according to the Sunrise instructions I had received.
Sunrise took over EBL on 1.1.2023.