Recommendation: DO NOT USE AUTO use HIGH.. NOTE this may or may not fix your problem but there is a 2nd issue with AUTO.
A/C's make noise. lots of it. even ducted "Quiet" ones are noisy
But if you set the thing on HIGH (Only affects fan speed by the way) your brain swiftly learns to filter and block much of the sound.. IN fact one of mine I actually CAN NOT HEAR after about 15 minutes and have to use other means to tell if it's even running. (The other one makes a different type of noise not so easily filtered).
This is why I run mine on HIGH.. Also when the folks a site or two over have a "Heated Disagreement" the White noise from the blowers keeps most of it out of your RV.. So long as they do not start throwing things and bouncing them off your walls.