Something similar happened to me and was the reason that I was sitting unevenly in the saddle.

For a good while, I had my seat height too high. I had thought that hip rocking would be the tell to let me know if I was too high but that was not the case. Rather, my body responded with a permanent lean to the right.

In my contorted state, I'm not sure that it would have been possible to professionally fit me properly other than to fit me to accommodate that lean.

I solved the issue by lowering my seat nearer to the bottom of my fit window than the top and then gradually working my way back up. That process took about three months of riding several times each week.