I had this same problem after my first knee replacement. Actually, I had some serious excruciating pain in the first couple of days after the surgery. It was from this IT band.
It eventually went away -- I can't remember how long it took - that was in 2015 - but I have had no issues for years.
Most of the problem as I look back was my fear that it would never go away. I was extremely anxious about having the surgery in the first place and only had it when my knee hurt so badly that I could not walk 50 feet without screaming.
That said, 8 years later, that knee, my other knee, my hip and my shoulder feel better than the originals.
Hang in there. I am betting this problem will resolve - my probability guess is 100 percent that it will resolve.
I had no physical therapy. I was just told to walk -- and that is what I did.
Best wishes! Relax! It will resolve!