Hey Brent my experience with the soreness and “odd“ sort of fatigue feelings is similar to yours. I have commented on hip runner a few times on this subject over the last year and a half since I had my hip done. Odd soreness, a little stiffness, fatigue, strained hamstring muscles, and like are all things I have experienced in different from my pre-hip surgery days.
Unquestionably, we are experiments of one… I find more stiffness following harder road running efforts and harder efforts in general. I find less fatigue and stiffness, note I am not saying pain, when I am doing gentler running on softer surfaces, which is what I therefore stick with most often ;-). Don’t be afraid to gradually push boundaries to determine what your body and hip can and can’t handle… My experiences that is the only way to find out. Most importantly, keep moving and keep living!