I ran into this issue described by cyknight. I had a doorbell connected to a Control4 CardAccess ZigBee Pro Extender Wcs10-x-zp that would send a chime to all the Control4 connected speakers in the house when the standard doorbell was pressed. I swapped out the doorbell for a Nest Hello. The issue is the Nest Hello requires constant power so a signal was consistently being sent to the CardAccess module whenever any 'event' occurred like any sound was picked up by the nest hello mic or there was a person who walked by. Every time that would happen the doorbell would chime. I attempted to fix this with my pro for weeks. We thought a Voltage 'filter' that only allowed the higher voltages of doorbell presses to pass to the CardAccess module would solve for this and eliminate the 'ghost' doorbell chimes but it would require extensive wiring. So I abandoned the project and simply route all the chimes through the Google minis and displays located throughout the house using Google's/Nest's native interface. You may want to explore this voltage ceiling regulator if you'd like it to work. Good luck.
