Definitely go after your quads and hamstrings that may be creating abnormal pull at the patellar tendon causing the patella to grind. Also assess your hip IR/ER because it may be that the “track” (femoral condyles) may be malaligned under the “train” (patella) and causing it to slide/glide abnormally. Don’t forget the quads up at the hip either and check tibial rotation as well. IF those are all normal then travel to the feet because most times that can cause all kinds of knee issues if your ROM doesn’t fall within the norms necessary for performance in and out of the archetypes. Today’s dailyrx would be a good start btw.