Have you removed the back plate? All functions: Left Turn, Right Turn, Constant on, Anchor Lock are a function of a magnetic field. If you heat the arm the magnet is mounted on and bend it up or down you can change the action. I haven't needed to do that with mine but it's possible. But... it takes some patience and tenacity to accomplish. Several of us on have have invested hours in trying to correct the MotorGuide screw up. In the end those actions have made the pedal better but I would not even remotely suggest we've made it "good".
It is possible to press the pedal down too fast and pass the magnetic field sweet spot. I would suggest you re-wire the Xi5 w/power and, with the back plate off, operate the foot pedal with your hand - slowly. This way you can see exactly where and at what speed the foot control operates best.
Xi5 control.png
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