Oh so you've already discovered the cause of sumping then?
Please tell.
Its been discussed ad nauseam on the forums, by people who have actual experience building engines and solving problems. The notion that the oil filter plays a role is just silly
So you don't know then?
If you do have experience building engines and problem solving please explain how a defective oil filter couldn't cause oil sumping by restricting oil flow and causing a buildup of oil in the crankcase.
Not trying to be a smarty pants but I would venture to say that if it were caused by a filter problem it would have been solved long before the third year of sumpers.