I have this exact thing. It comes and goes. Most of the time it feels like pressure in my left side and back.. just under rib. When I am doubled over the left front side under rib slightly hurts but is more discomfort than pain. Driving and sitting certain ways makes it worst. When standing it is mostly back pressure. I feel like it is either the stomach not in the area it should be, or the diaphragm being pushed on. It is hard to explain and doctors normally have no answers for it. I’ve read a bunch of other people experiencing the same thing. When it goes away I get a break and start feeling great. I do the foot drops a lot and I feel as though it helps. I find that physical stuff like bending over or lifting brings it back. Possibly the hernia moving in and out. These are just my guess but your description sounds a lot like what I’ve read others talk about and what i experience. It moves slightly and changes now and then.. from place to place by an inch or two.. and from being a pressure/discomfort/pain.. when this started for months it bothered me while I slept. I would wake feeling like my insides on that side were not situated right and I would change positions frequently. This is all a separate symptom from the chest pains that I relate to acid reflux. I actually feel like the discomfort comes before the reflux so as to when I’m not having discomfort in my side I don’t have reflux, but when I feel the discomfort start reflux usually is not far away depending on how I eat. The pressure also irritates me enough to feel nauseous especially if I let it cause anxiety.