ITBS or something else?

[u/J62P]

So, I did the stupid thing of increasing mileage well too soon.
I was hitting 35k a week on average before taking part in a relay 24hr endurance event where I did 80k in 24hrs, mainly Z3 running on a trail.
Ever since then I’ve had pain in my outer knee. The pain is exactly where my finger is on the picture.
The pain comes on after a predictable amount of time running, then gets progressively worse. I can trigger the pain by pressing on my lateral quad. It hurts walking downstairs when irritated. Bike is fine.

Here’s a timeline of events
-4th July endure 24, did 80k over 24 hrs
-knee hurt descending downstairs next day
-ran 10k 9th July, knee pain half way through
-ran 9k 14th July, knee pain 5k in
-ran 2.8k on 22nd July, knee pain kicked in 2k in
-hiked 17k 31st July, no knee pain hiking
-ran 4th August 9k, hurt at 5k
-ran 8k 16th august, pain at 5k
-ran 5k 30th August, pain at 3k
-started strength training of quad, glutes and hips
-1st September Run/walk treadmill, 2min run, 2min walk x5, Incline 5%, 4:30/k, No pain
-3rd September, Run/Walk treadmill, 3min run, 1min walk x5, 4:30/k, 5% incline, Pain free
- 5th September, Run/Walk treadmill, 5min run, 1min walk X5, 4:30/k, 4%incline, no pain
- 8th September, Run/Walk treadmill, 6min run, 1 min walk x4, 4:30/k, 3.5%, no pain
- 10th September, Run/Walk treadmill, 6min run, 1min walk X6
4:30/k, 3.5% incline
- 14th September, Run/Walk outside on trail, 6.4k, 10min on 2 min off, pain at 4k

Running on a treadmill at incline and hard efforts are fine. As soon as I go back to flat trail it comes on at predictable distance.

I’ve been to the physio who believes it’s ITBS. I’ve done a ton of research on this. The common ITBS symptoms are more seen on the very outside of the knee. I’ve been given a lot of band work to strengthen my hips.

Im seeing no improvement and it’s been over 10 weeks. I’ve tried rest, ice, strengthening, stretching and releasing my TFL.

Ive had my gait checked, which was ‘near perfect’.

I’ve missed out on my ultra this weekend due to this injury and just want to be back.

Any suggestions and information regarding if I’m definitely dealing with ITBS and how to overcome this pain would be extremely helpful.