Call muted with navigation, but caller still hears me

For about three weeks, when I am in my car and the navigation is going, and someone calls me, every time the navigation kicks in to announce a turn or something coming up, the call goes mute - but the person on the other end can still hear me. The mute button is not enabled. I have to hang up, and recall to be able to continue the call, but as soon as the navigation kicks in again, it goes mute.

I have not changed any settings on the phone, nor the car. This just started randomly. I have an iPhone 12 Pro Max. I have never had this problem before. Any help would be greatly appreciated!