Just purchased a new 2019 Audi with the new MMI release. I also got Oreo on my Moto G5Plus about the same time. Anyway...
DC works fine in most cases and I am using BT streaming, not android auto because I don't want to plug in all the time... The one instance where DC gets funny is when I want to FF (I have set to 1 minute). The first time it works fine. If I do it a second time (FF thru a commercial), it will end up stopping playback. I have to "mute" from the car TWICE and audi will resume. In my previous car - 2013 Audi MMI, I could FF over and over again. I believe a change was made to the code as one of the developers had a new ford that exhibited similar issues. I would guess there is something in the MMI that is different again. Would certainly provide any logging or try any feature to help determine the issue...
Try deleting the pairing from your vehicle/headset BT device and your mobile device, then re-pair again & reboot your device
I have removed and re-added phone to BT in car and rebooted phone. Still same issue. Every 2nd FF results in DC being paused. 2 pauses from Car will get it running again.