If water is getting to your filter but not the pump, then something is backwards! Water runs from the drain/skimmer to the pump's skimmer basket, then from the pump to the filter, via the multiport. It sounds like you have the drain water going to the filter first, then to the pump.

My point? I cannot see how it's possible for the filter to be filling but water not going to the pump. Can you post pics and indicate drain/skimmer versus return lines?

Carl