I’ve had it for a few years after doing an mtb ride with the dropper post stuck down. stayed off the bike for 6 months thinking it would heal on it’s own (whatever it was). Eventually went to doctors and then sports physio on NHS. Didn’t take the physio particularly seriously and only saw slight improvement. physio on NHS finished and I just stopped the exercises. 8 months on whilst doing winter mountaineering it was causing me issues (mostly jarring by slips, walking in crampons, foot breaking thru crusty snow etc) I decided I was a liability to myself doing these sorts of activity with a dodgy knee, so decided to take the physio seriously. looked up some routines on you tube and started doing them again but this time properly (ie regularly and increasing reps and using weights) I also included IT band stretching. Sorted it out, but has since come back but in a much lesser degree, so think if I want to always be completely clear then I’ll have to keep doing exercises and stretches occasionally, which I probably won’t, of course.