First, “finger screen” your Polaris. Next, check the floats. They may not be aligned properly or might also be weighing it down with water.
Your Polaris or other in-pool cleaner is working hard to tackle leaves and debris. Be sure to check the debris bag for holes or tearing and empty the bag when full. Some parts on the Polaris unit are designed to be replaced. Tire treads, wheel bearings, and hoses should be routinely inspected and assessed for normal wear and tear. Lastly, inspect and maintain your booster pump like all other equipment.