Shoulder pain in under swing on pbars

I'm a highschool gymnast and I've been a pommel specialist. Recently i've been trying other events just for the fun of it but for some reason whenever i swing under the pbars it hurts my shoulders. I can't even do a glide kip because when i go into it it hurts a lot and feels very awkward. I can do a kip on high bar and rings perfectly fine and can do above bar stuff on the pbars like swing to hands, press,etc but this is just weird. Is it that I'm too weak or is there something wrong with me?? I really want to learn p bars but I can't because of this. There is also some pain while doing rings although not as bad.

Where is the pain localized?

Daniel Burnham said:

Where is the pain localized?

Area opposite of the armpit if that makes any sense? Is there some kind of picture you want me to point out where the pain is?