Self-poison cannot work

I use "Scold's Bridle" helmet and "Apep's Supremacy" Focus to deal self-inflicted poison for my character.
When I get poison status, but my character no HP loss.

Here is my testing video at 1:26 show this bug.
https://youtu.be/hgTcFiYVCBQ?si=VLd1bEtl0wncUAC6&t=86