DS-KB8112-IM (two way) audio not working

Hi all,

First time posting here, trying to get my issue resolved as I'm out of ideas.
I've installed and configured 2x DS-KB8112-IM and 1x DS-KH8301-WT.

The first DS-KB8112-IM is working without any issues with the indoor station. But the second one will not work properly.

To describe the issues in a bit more detail:

1. When you press the button you do not hear the ring/dial tone (its silent)
2. You can hear the person talking into the doorbell
3. The person at the doorbell does...

DS-KB8112-IM (two way) audio not working