All the cases of bleed removal was on the enemy being attacked, so I guess that's working as expected. When I was trying self-care though I did it when Jean had high enough OT built up that I should be able to see the change (like 12 or so). I didn't choose actions very efficiently so it was common to get some OT buildup.
EDIT: Also I forgot to mention, I think Kamui and Avicenna's headshots have different OT gates and effects, which was unexpected for me. Another thing is that OT is consumed even if I use a skill when below the OT gate (the manual says it is subtracted if you use it when above the gate)