CAME BPT E/272 feedback sound when answered by app

I have a CAME BPT E/272 which I am trying to connect to a Ring Intercom.

Whenever I buzz the intercom and answer with the E/272, it works fine.

If I try to answer with the app, I keep hearing a loud feedback sound, as if the mic and speaker are feeding into each other. I can talk over it and be heard by the person buzzing as well as hear the other person talk back but it’s extremely uncomfortable with this feedback sound present.

Soon as I hang up, the sound goes away. Muting the app mic or adjusting the app volume for mic and speaker as well as the hardware mic potentiometer on the E/272, makes no difference in reducing this feedback sound.

I have wired:

Intercom A cable A2 to 6 on the E/272
A5 to 8
A3 to 4
A1 to 5
A6 to 7
A4 is not connected to anything.

The above worked well for the E/272 predecessor with the same wiring, the BPT SA/72

Any help, appreciated!

Θυροτηλέφωνο-bpt-e272

Hey @groovy100. For advanced wiring questions like this, we have an intercom support team that you can reach out to directly at one of the numbers here. I’d recommend reaching out to them if you don’t receive an answer from another neighbor who may have encountered a similar scenario.