Quoted from Spraynard:
I tried this fix with my JM and it didn't work, unfortunately. In my research, it seemed that picking up multiple balls was a common problem on JM. Never found a fix before selling it. Tried everything.
This is not a common problem that all JM have. It indicates your hand is sagging. You'll need to do something to raise it up whether it's just the t-nut or not. Saying this is just how it is isn't right.