How long ago did you have the surgery?
Since you are working from home, can you figure out a way to support your shoulder? Maybe rest it on a pillow or something?
I had shoulder surgery - not a replacement, but to repair a labral tear - and every person I talked to about it said that shoulders are really, really tough to heal. It's been 4+ years for me and I'm sure my shoulder will never be the same. Joints are just really tricky.
Definitely let your doctor know what you are feeling. If you are beyond the PT, maybe they'll want you to do more, or maybe they'll give you some support contraption.
Let us know what happens, and I hope you feel better!