Flipbook collision doesn't work on a paper character, maybe a bug ?

I created a paper character and I would use the “collision each frame” from the flipbook to have precise collision but seems to not work.
I tried to set the capsule component radius and height to 0.0 to only have the flipbook collision used.
Is it a bug from unreal engine or I missed something ?

For collision interaction with the ground, the flipbook will always use the capsule. This is not an error.

Not possible to have precise collision ?