The pump could be jamming more particles through the filter with the pressure, and I also think it's fats. All my filters have clogged cuz of fats. You filter on a nice hot day when the fats are liquid. Temp goes down over night and they all accumulate at once in your filter the next morning. Thats my knee jerk thought.

I dump through 5 micron sock filter into 55 gal drum. Heat to 90 degrees for several days. Turn off heat. Rotory pump thru 10 micron goldenrod into car. I change filters when I think of it. There is alot of suspended water in WVO that'll drop out with some heat, if not the other kind of water (the non-suspended evil kind).