I have a Pentair Prowler 820 that has recently begun getting itself stuck in the shallow ends where the pool floor and walls are at 90 degree angles to each other. It's getting stuck with the two rollers spanning the wall and floor (like the robot was running parallel on the wall and then just slipped down). When it does this, it's then spilling out all the debris that it has picked up, creating a pile of Crud wherever it gets stuck. The cartridge that holds the filters has begun to separate and I have ordered a new one (arrives late next week), but is there anything else that could be causing this? This would happen every once in a while last year but this year it is happening a lot (like every time it runs). Any help would be appreciated.