I have the same Polaris and I've had a lot of problems with mine. There may be a ton of things causing it to hang up, but IMO, the most important thing is to make sure your back-up valve is working properly. It should cycle every few minutes to pull the Polaris off of whatever it is stuck on. I think getting stuck is unavoidable with these things, but if your back-up valve is working, it won't stay stuck.
Before I replaced mine, I noticed that even when it wasn't "activated," the back-up valve had a steady stream of pressure coming out, which I think was interfering with the operation of the Polaris. Once I replaced it, it got stuck less and it now pulls itself off of whatever it is stuck on.