I'm having issues where the pose I want to mirror does zero to bare minimal change, as in the arms may move slightly but nothing is mirrored it stays the same. My old pose was scrapped and remade simply because when I use the x paste pose mirror it deforms everything. I recreated a new armature with proper naming conventions (.L and .R) Everything seems to be in order however the pose does not mirror or move at all. Is this a roll problem? Or something else?
(Link to the Blend file)