Ritto 17230/.0 + Opener doesn't recognize door bell

I have a Ritto 17230/.0 in an apartment building and have installed the Opener according to the instructions. However, while the “Open Door” button in the app works, I get stuck when trying to open the door by ringing the bell – it doesn’t work.

I have found a couple similar threads, but the solution there seems to have been incorporated into the official instructions already, so my setup is already as described there. I will attach a picture before setup here, and a separate comment with the setup after installation.

Does anyone have any ideas what the problem could be or how to solve it? I’ve also separately contacted Nuki support.

After installation. In words:

Nuki Green + Nuki Orange into Intercom a
Nuki Black + Intercom Black into Intercom b
Nuki Yellow + Nuki Red into Clip (1)
Intercom Red into Clip (2)
Intercom Yellow into Intercom ED1 (unchganged)
Intercom White into Intercom ED2 (unchanged)

Support has been helpful and quick, but unfortunately ultimately to no avail and they have given up now.