Knee creaking

Hey everyone! This is my first post here, I am posting as I have been having trouble with my knee and just wondering if anyone might know the problem. I am 21 years old 70kg and relatively fit and athletic. November 2019 I fell off my bike and grazed up my knee, particularly the left knee. This is when I first noticed what sounds like a creaking/crunching noise when I squat. initially it was only occasional, now it is pretty much all the time, however I have no pain actually associated with the creaking/crunching noise. After a day skiing or particularly running, my knees (especially the left) do get sore. I regularly ski, mountain bike, yoga and hit legs in the gym twice a week, am squatting 3 x 10 of 80kg with no knee pain during the squat and minor soreness after I finish in the gym, although more often than not I don't get any pain even following. My main concern is occasional knee pain and the noise is loud and sounds horrendous I just know somethings not right. I have been going to physio for several weeks now, we have done massage, acupuncture, cupping, ultra-sounding, strapping the knee etc. which feels really relaxing for it and eases any soreness at the time but hasn't changed the creaking at all, my physio is really awesome and experienced, but we haven't really identified what the problem with it actually is, I think from here he is referring me to get an MRI done, but not sure how far away that is. He has also applied pressure to all sorts of positions on my knee while I do a one-legged squat, and he has commented its strange that there are many positions he pressed where he cant feel the crunching at all. I don't know if he is just concerned of scaring me if it could be a big issue or it could only be minor, but I really want to know what is going on, does anyone have any ideas on what it might be? any knee specialists out there who may be able to explain? cheers!