no cps1 & cps2 share the same driver there are very little differences between the 2 actually...
Ok, I could reproduce the problem even if I can't do it 100% of the time on the left, I am also at 0% on the right, which is very puzzling !
No idea for now...
What I did to test that : a 2 player game with shuma gorath against himself, so I switch the gamepad to test 1 or another, and I have the cheat "infinite timer" if I need more time...
And very strangely at a time every tlme I loaded my savegame the left shuma did this famous move as soon as it was loaded when I am sure I did the savegame with nobody moving ! I overwrote the save in frustration, but maybe I should have kept it to understand what happens here... (actually it was not in frustration, it was because for some reason the change in commands had made that one of the joystick buttons was also a button to create a new savegame... ! Normally there is no joystick button mapped there, so no idea how it happened to be here, but my save was destroyed anyway!) something very strange for sure, but it's not easy to track these special moves !
It's not the speed hack neither...