I may have the same issue, both sides. As I understand it, new prosthetics are porous, so your body can literally grow into them. I was running 10k races after six months, and felt great. So great I decided to ski moguls. I overdid it, and now get very gentle soreness from walking up two flights of stairs, and calf cramping at night (even after no exercise). I no longer run, but can at least ski intermediate slopes, with some advil. In a nut shell, I think I broke the initial bond between the prosthetic and my leg, and it was replaced by permanent scar tissue. My surgeon warned me… Good luck.