This is something I’ve run into previously but it’s yet another minor feature I never really pay much mind to or care about functioning on a day-to-day basis. Messed with it again today and thought I’d bring it up.
Basically when using the voice assistant function in Sync 3 outside of using AA/CarPlay (ie: The function that triggers if you hold the voice command button on the steering wheel for a few seconds), for Google Assistant it goes so far as to show up as an active voice call on the IPC, does the ‘ding’ you normally get from Assistant triggering and then waiting for your command. Right about where it feels like it should provide the appropriate response, the ‘call’ drops and nothing comes through Sync.
Currently on 3.4.21265 but this has happened on previous versions. This is also with a Pixel 4a.