I have occasionally run into an out-of-sync situations like this a few times. it's usually when one of the devices/apps has been idle a little while and a routine of some sort is running. sometimes things get out of whack, but nothing is wrong and it doesn't impact the routine running on the AA+. I think it would be best if ZWO were to bake in a full GUI refresh if a device connects that's been idle more than a few minutes.
The workaround here is simply kill the app and relaunch and it will be 100% in sync, I've never not had this work before and I constantly use two devices during the same session.