I consulter the owners manual for this model. This is what they suggest.

First, remove all of the air from the cleaner head and stop all air from entering the pool through the return lines. Also, if the head and hose are covered with bubbles, give the hose a good tug. This will release the air bubbles and allow the pool cleaners to settle son the bottom of the pool. Also, the cleaner head may actually be being lifted off the bottom of the pool by the hose or the pressure in the return lines. Make sure that the hose stays untangled and the pressure from the return lines is not too low (not enought pressure to power) or too high (too much pressure that cause the unit to lift off the floor).