The skimmer net prevents larger impurities (leaves, hair, etc.) from getting into the pre-filter or supports sand filters that have a pump without a pre-filter; this prevents the water wheel from getting stuck in the pump.

This is normal behavior. Compared to other alternatives, the Intex skimmer does not have a lock to prevent it from floating up. To counteract this, weigh down the strainer basket or remove these parts from the skimmer housing during bathing.