Create a part whose top surface is sufficiently high enough from ground to jump properly from. With PGSPhysicsSolverEnabled set to false, you can jump from anywhere on the block at the normal jump height.
However, when setting PGSPhysicsSolverEnabled to true, if you run along the block to as close to the edge as possible and jump, your jump height will greatly decrease.
Video of bug: https://www.youtube.com/watch?v=01YZKFgcf3g