Ring Intercom doesn't works with Comelit 6721W

Hello everyone, I installed a Ring Intercom 2 months ago with my Comelit 6721W. Everything works correctly except the calls, doesn´t works. I followed the wire instructions connection the 9 and 10 wires but I cannot hear the people on the other side, and they cannot hear me....when I trying to install the dispositive, I cannot pass the final test by this problem but I clinck on the next button and skip it, so the other functions are working but not the most important for me...something that I detected last day, is when I talk by the app on a call, I can hear my voice very distorted with a little lag...I started a ticket with the support but I didn't receive any information since one months ago...and they doesn't give a solution... In conclusion...Ring tell me that Ring intercom dispositive was compatible with my intercom Comelit 6721W, but under my opinion, this is false or they don't give me the way to solve it. Can anyone help me please??