Nuki Opener Ring Suppression

I Have a opener problem with the ring suppression.
i think i found the cause of the problem.
i have now a Ring intercom parallel with the Gong.
Only the Gong will notice the Ring Signal not the Intercom when Ring to Open is pressed.
So i have the fealing that the Gong (Honeywell DCP917S with DC917SG) is to sensitive and will pick up a noise or peak when you close the “relay” of the ring supression.
do you have an idee how to filter the noise of this? maybe with an Resistor Capacitor low pass filter ?
What will be the Value for the Resistor and capacitor? or is there a better way?