You may have a Navigator with the 4 feet and wings, people call them R2D2’s. While the pump is running carefully put your index finger, the long one, in the hole on the bottom of the cleaner try to feel the water wheel paddles moving, if not then try to move the wheel with your finger.

If it starts moving then all is well. Sometimes grit or glass gets inside and stops them from moving. Rodents work well too. Turn it over holding under water to see if you see a tail!
If the wheel is clear, check your filter it likely needs cleaning since these cleaners are suction side and affected by dirty filters.