I'm so tired of this band. Finding a new a surgeon tomorrow.
I would want the new surgeon to be checking out your band, just to be safe. They'll probably want to do an EGD in addition to the upper GI. Together, they should get a better idea of exactly what the issue is. It's quite possible not to really know what's going on till they get in there to remove it.
When my aunt started her revision testing, the tests showed a very slight slip. When they got in there, a lot more was discovered (I don't recall specifically) and it took 6 hours to remove her band.