Squeaking rear brakes after handbrake use?

I figured I'd post this here rather than WK2 forum (2020 Grand Cherokee). After using the hand brake (took a while to figure this out), for two days or so, there is a pretty loud high pitch squeak coming from the rear, pitch comes and goes with rotation of wheels, but only at slow speeds after startup. After driving, it goes away, then when sitting, it squeaks again at startup during first roll, and goes away, and disappears even when going very slow. After about 2 days, it goes away completely, even after startup and roll, until the next time the hand brake is pushed. If I do use the hand brake, the cycle starts again, for two days I get a squeak every time I start driving even if I don't use the hand brake. Again, it goes away completely after a couple days and there is no sign of any squeak. Is there some physical adjustment that can be made? Any other reason? Crazily, I had a squeak which I thought was differential months ago and did that in the service, and also my rear brakes are brand new (less than 6 months now), but this particular squeak is still there. Dealer says that my Jeep is tip top shape, they can't find absolutely anything wrong with it anywhere (let alone this particular problem).