Apologies my ranting, but things should not be this difficult.
I uninstalled everything and reinstalled fresh versions, just for the heck of it.
Pasting is back to a correct position. Phew!
But reversed clip after Mocha AE is not at correct frame. Nearly there! Have to test more.
I can say, I have never experienced this much difficulty.
Have you tried precomping the reversed clip, then tracking it? Please try it and report back.
cropped screenshots for helping us diagnose the problem is not a good idea. there's information in the specific of this situation.for example, the most notorious gotcha when pasting mocha masks is the duration of your source. if you trimmed your layer, and went to mocha to track just that part, when you paste - it will paste with an offset if you are not careful because mocha treats creates keyframe from the start of the source footage, not just the trim.
what you should do before you paste from mocha is click twice on your footage layer in your timeline - it will open the layer window. now go to to the first frame (home) and now hit paste! you have now pasted your keyframe from the beginning of the SOURCE. not the trim. now your masks should line up.
Did you try what Roei suggested? Please let us know.
Very busy at the moment.
I will try things soon and get back to you.