Anyone else had any issues with cruise control not being able to maintain a set speed under certain conditions? It's always done it from time to time but usually only going down slight inclines but it's recently started doing it on flat ground with cruise set at 65. The speed will drop to 64, it'll rev up and get up it to 65-66 then let off, drop to 64, speed up again, and back and forth bouncing back and forth between ~1700rpm and ~2100rpm. Almost like it's gear hunting but there aren't any gears and I'm going to guess this is around the boost threshold too because it's pretty noticeable. (18 Touring AWD with a little over 28k miles).