2+ years of mysterious right oblique/upper abdominal pain. MRI, CT, X-rays normal. I’ve tried almost everything.

I’ve been dealing with a really frustrating issue for over 2 years now and I can’t seem to get any real answers. I’m a long-distance runner, and it all started after I was repeatedly coughing hard while twisting to the right trying to get my abs more sore/worked. After that, something in my right side never felt the same.
The pain is located in my right upper abdomen/oblique area, more of a broad region rather than a single pinpoint spot. The weird thing is that I have zero pain at rest. I can sit, stand, sleep, and do normal daily stuff completely fine. The issue only shows up during exertion, especially running or anything athletic.
When it flares up, the area gets extremely tight and knotty, almost like everything locks up. It gets to the point where I literally can’t get my fingers underneath my right rib cage the way I can on my left side, like something is physically restricting it.
Over the past 2+ years I’ve gone through a ton of treatment and testing. I’ve had MRIs, CT scans, and X-rays, all of which came back normal. I’ve done around 100 physical therapy appointments, chiropractic work, scraping/IASTM-type treatment, stretching, mobility work, diaphragmatic breathing, ice, heat, massage, and I even tried Western medicine approaches as well. I also had an injection at one point, but it didn’t help and may have even made things worse.
I also took about 3 months completely off from running to try and let it heal, but when I came back nothing had really changed.
At this point I’m just trying to understand what this could possibly be since nothing is showing on imaging and no treatment has really fixed it. Has anyone experienced something similar where the pain only shows up with activity and everything is normal at rest? I’m wondering if it could be something like a chronic oblique strain, fascial restriction, intercostal issue, nerve entrapment, slipping rib syndrome, sports hernia/core issue, or something else entirely.
Any insight or similar experiences would really help. I’m open to anything at this point.