Try, not looking for issues at the knee itself. Look at the MUSCLES that control knee joint movement. Every trigger point you find, shortens the range of motion. And pain occurs in the joint /s
Sometimes / often, it’s the opposite muscle of the one you think…
Eg
I had Achilles tendon pain, right where the skinny part is.
Solution that solved it for good, was fixing the Tibilius anterior muscle
I spent 80% of time on tib ant, and 20% time on Achilles