I have this condition with my winged scapula that’s been here for as long as I could remember. I didn’t even know it was abnormal until someone pointed that out to me. I’ve tried the usual stuff for it. Pec-minor stretching, serratus anterior strengthening, and nothing has worked. I honestly doubt I even have a weak serratus, I’ve been doing plenty of overhead presses/pullovers for the past 5 or so months, and I even threw in the isolations like scap push up plus, etc two months ago. They don’t actually restrict movement/strength in any way as far as I can tell, though.
I thought perhaps it might be an imbalance between my back and chest muscles that was causing this, but I’ve been doing two intense back days a week, and only one chest day (even then only half that time is spent on chest). I also look like I have a slightly rounded forward shoulder, but I suspect this is something brought on by the winged scapula rather than muscle imbalances. My rear deltoids look disproportionately large when flexed in fact.
These are some photos of me when relaxed.