I just recently got my 2014 mustang v6 auto and noticed that when I put it in park sometimes it shutters and the rpms drop to around 500 then bounce back up. The air fuel ratio drops when this happens. I checked the throttle body and it’s super clean, I cleaned the mass airflow sensor, and put a brand new filter in it. Any suggestions on what it could be? Thank you

Here’s a link to the car doing it^^^^