Iphone 13 : low volume & feeble call audio via Carplay

If I make or receive a call using CarPlay (connected to my new Brezza 2022), then ALL my callers complain that my voice is way too low and they couldn’t hear me. People using hearing aides like my dad struggle multifold.

Whereas, if I disconnect Carplay, and selectively use only Bluetooth car connection to make/receive calls, then my voice is super clear, people hear me alright.

Tried carplay with other iphone SE too, and the result was no different.

just a side note, this issue does not occur if I use Android auto to make calls, tried with my wifes phone.