I finally figured out how to keep my foot pedal in place. I tried a lot of suggestions, none of which worked for me.
What finally works is using a small bathroom mat -- the kind that fits around the commode bottom -- turned so that the foot petal fits into the U-shaped cutout. I haven't had to chase my pedal since.
My apologies if this proves not to be my own sheer genius :lol: but only my subconscious memory of something I read here that only now managed to surface.