Two new pistons.System bled. When the top opens one piston seems to lower slower than the other.This makes the top lopsided and kind of twist when its opening.What causes this?

I would think that there would still be air in the system from the pump. Or, a line is not tight enough and allowing air to enter before folding. I'm not familiar with the top setup, but I do have experience with hydraulics with jet aircraft and this what it would seem to be for me. Just my .02.

I have messed with many tops.... 67cruisemaster is correct
note is always recomended to replace them in pairs as you have done