My swimspa is just a few months old. There is a filter in 2 different corners of the tub. Typically when the pump is on low and especially high, you can see both of the plastic prefilters get sucked under the water from suction. At the moment the one on the right in the photo doesnt seem to have enough suction to pull it under. I even swapped filters and have the same outcome so i dont think its a dirty filter however i cant notice any different force in the jets on either side of the tub (which may be irrelevant). Any ideas? Thanks