Doorbell Pro and NICOR Prime Chime 2 Wiring Question

I have a new construction home and it has the NICOR PrimeChime 2. I wired the Doorbell Pro and it mostly works, however, when i try to speak audio through the doorbell from my phone, the PrimeChime sounds off as if the doorbell was pressed. NOT the Wyze Chime, but the Nicor chime that should theoretically act only as a transformer.

Anyone know why this is? I purchased a standalone transformer but have not installed it because I learned that installing a transformer in place of the ‘all-in-one’ Nicor unit will create a code violation/fire hazard.