im having atc problems too. look on msfs forums . its being talked about. i believe its SU11 problem. it messed up the entrie in-sim audio. i can no longer hear atc controller instructions, i can only hear my voice. when i click on the atc menu text options like switching over frequency, the radio never changes. im having the same atis problems that u mentioned in ALL payware aircraft. have a loon on MSFS forums...
Can’t Hear ATC and Other Aircraft after SU11 - Bug Reports / ATC, Traffic & NAVAIDs - Microsoft Flight Simulator Forums