I too had pain after one of my hip replacements. I had been limping for years before it was determined that both hips and not my back or my knee were the problem causing much of my pain. The first surgeon "didn't believe PT is necessary" for hip replacements, so even after new hips I continued to have back pain. Some years later, long story not relevant here, both hips were replaced again and the new surgeon ordered rehab therapy to get me moving well.
The excellent PT studied my gait, and determined that I had been limping so long I was causing multiple issues.
Step one in the process was brand new, supportive shoes. All of my old ones were unevenly worn based on my lean and my limp.
Step two was an evaluation of my walk - from front, back and side, on level ground, a ramp and stairs.
Step three was making conscious efforts to stand straight, walk evenly, and look forward.
The final step was strengthening exercises and core exercises to support my new stride.

Fast forward over 12 years - my hips are great, my back only hurts if I neglect exercise too long, and I am working on my leg muscles to prolong the life of my bad knee.

Can you talk to either the PT or doc about evaluating your gait? And have you replaced your shoes since surgery, at least the ones you usually wear when active?