The foot bone, instead of staying flat when I move the IK bone up or down, rotates. I tried adding a copy rotate constraint to the IK mover bone that doesn't rotate but the foot bone still rotates.
Here is a link to the file https://drive.google.com/file/d/1A7xcXlophIFLhbRQHUgmO6LDq9KeK0WW/view?usp=share_link