Idk where to send bug reports, but I just got a weird bug fighting Hard AI Ji-Yoon as Belmont. About 7 seconds into the match, she got herself stuck in the top-right corner, and was unable to be hit. She wasn't moving or doing anything, and I wasn't able to hit her normally. I even went as far as killing a lot of time by organizing all the blocks, and she still didn't move. She was unhittable by normal blocks, but activating Belmont's special (skull block popping), she was able to be killed. Not sure what caused this, might be a random rare bug, but hopefully it can be fixed?
EDIT: Just to make the report as accurate as possible: It was Standard Training Room.