D2 poney clutch

Possibly something wrong with it - it is supposed to over-center. My guess is that in adjusting in both directions, you either undershot or overshot the sweet spot. Doesn't take a lot to adjust it from not enough to too much. If you have the patience, you can adjust it one notch at a time all the way in, and then having counted how many notches, then go back that far then start adjusting again one notch at a time but this time outwards. It might take 10 mins but it could avoid an unnecessary disassembly

as Neil said, there is a very fine distance of one pin hole either way of being correct for the clutch to engage or not especially when the clutch fingers get worn and flat spotted.
If you turned the adjuster several holes clockwise or it was that way when you got it you now need to keep backing off the adjusting collar--suggest adjust it out to loosen the clutch engagement position so it does not lock over and advance until you get the resistance/lock over needed.
IF the clutch is adjusted too far in it will not lock over either just as you describe.
Either this or Neil's method will get you there.
Cheers,
Eddie B.