I’ve had the same problem and since nothing seems to be wrong I think it’s nerve damage from the surgery, some people don’t have any issues but others do. When you cut into the body the muscles and nerves are damaged and eventually they will heal but it can take a while for them to heal but they’re never going to be the same especially if you were older when you had the surgery, another example is when someone breaks a bone or tears a muscle, the injuries will heal but there’s always some residual pain that can come up throughout your life, it seems that you are doing everything possible to help you with the pain.