Hi! The shoulder pain post surgery is something I experienced as well. The drs office said it was likely post surgery gas.
It worsened in the evening, and faded during the day, like someone else mentioned. It took almost a year And a half to get it behind me.
I had / have a lapband and found it to be a rather common issue post surgery due to the phrenic nerve. Understand other wls can have this too. I recognize sometimes it can be eating too fast, however that’s the common go to...it’s gotta be something you / me/ we / Aren’t doing right.
When I found out this was more common than was not and brought it up to the office, the approach was - duh, of course it could be a nerve.
look up the nerve and become aware. I really hope it helps you get some clarity and comfort knowing it just might not be that you are “eating” too much, too fast, too soon, too late, not chewing well enough, ate something you shouldn’t have and all the other things that we tend to talk about. Best of luck to you.