I have an Elvox 6601 video intercom. Tried all day to make it work with Opener, using vendor Generic / model Bus. Same result as yours: gate doesn’t open and during configuration the button press is not intercepted.
Here is a picture of the working system and the meaning of the connections from the manual:
https://download.vimar.com/irj/go/km/docs/z_catalogo/DOCUMENT/MI49401083A0_R00.82145.pdf
I think the connections are ok, but the protocol is probably not compatible.