After regeneration I don't want the player to have the post regen damage reduction for longer than maybe 5 seconds. I've set it to 5 in the config, but i'm still in post regen for a long time after I regen. Any idea why?

This is for 1.16.5, I want to use it in the new mod pack I'm creating but I can't have people that invincible for that long. I'm making an altered version of my current mod pack https://www.curseforge.com/minecraft/modpacks/jetpack-cat