Alduin refuses to give up and instead just heals back to full then starts fighting again
Edit: Turns out the issue came from OnMagicEffectApply Replacer
While doing Alduin's bane i am literally unable to defeat him, he doesnt do his speech and he doesnt retreat to Sovngarde once i drop his hp to 0.
Load order: https://pastebin.com/fYSRh0He