When on the 1550 wing how fas t were you going? Try to go at least 20kmh or more. You could be too slow and the wing is still not in its proper AOA.
I ride a 2022 Cabrinha code 5’8".
I put the foil all the way back, and my front foot is often on the front of the pad. I can move it back a few more inches than this.
move battery pack between your foots, had the same problem but big difference , much more controle, once i moved it in the middle of the board. (i use foot straps attachement to fix the batterybox on the board) now i works great with a flipsy 2 balde fold prop, gong xl frontfoil and xl stab. but when i change prop to flite 3 blade prop the moment i start lifting my nose dives and i go over the board. i guess my stab is at a bad spot after the prop and in some vortex turbulentie creating a low pressure above the stab. gone change that distance : maybe lower my stab/rise my motor/shorten fuselage/propduc/ …