After dying and possessing a (skeleton or zombie) and curing myself, will become immune to all damage. Also my origins and classes will go away- if I check I will have "no classes" not even normal human. While in this state I will have creative mode-like abilities while in survival. If I reapply my origins (including the soul type) the invulnerability ends and I can be hurt as normal.

Minecraft fabric 1.18.2 requiem-2.0.0-beta.9.jar

I also noticed this but if you cure yourself before relogging then it's fine. Also if you relog after curing yourself in the invincible state you will get to re-choose your origin, soul type, and class.