chakster
If the OP bought this cartridge new, he should check with his dealer for a suggestion. If he bought the cartridge used, then all bets are off.
You have never mentioned tracking force you’re using for this cartridge, this is number 1 thing to check and adjust ...He said he tried raising VTF to 10 percent over the recommended maximum, which should put him at 2.2 grams. So that doesn't seem to be the issue, provided he's measured it accurately. I think Raul may be correct that the problem is in the cartridge itself, such as the suspension.
If the OP bought this cartridge new, he should check with his dealer for a suggestion. If he bought the cartridge used, then all bets are off.