Whenever I’m doing a a kneeling hip flexor stretch/lunge and I contract the glutes, I start to feel my IT band tighten up right above the knee (on the side).
Don’t forget a large portion of the glute attaches on the it band as well. So contracting the glute may be more directly involved.
I’d try to spend some on the edge of the pain cave smashing those lateral thigh tissues. Try to restore some slide and glide between the it band and the adjacent tissues. (For the record I hate this)
Smash the glute and TFL
Play with this
Do give this yoga vid a try