Easiest fix - get a good C kite
Hadlow Pro ideally, but Fuel a good option!
Other tips - edge super hard before you pop, this will force the kite hard to the edge, giving it a good distance to drop back whilst airborne = slack. Your board and technique matter a lot, as you can 'slip out' of the edge which undoes all your hard work.
You mention the bar getting ripped out of your hand after completing the pass - that is very strange, before the pass is common, but not after... Are you sure about this?
Also are you riding in gusty conditions? This could explain the big differences between attempts.