I have the same PJ, and I don't know whose is more "typical", but mine is very different from yours. The two knobs have a LOT of "slack", at the very least there is a ton of slack if you want to "reverse" direction before it "catches" again.
Is yours not like this? If not 100% sure, adjust to the perfect spot, and rotate it backwards gently until you're in the "slack zone"?
Well, I imagine you would immediately have known if yours was like mine, and therefore that you must be right that yours isn't after all. I imagine a remedy shouldn't be *too bad* figure out, as it is mechanical and not electronic, but who knows.
Please contact JVC and report back what they say?