Looking at the screenshots, it looks like he had a 50% miss chance, which is indicative of being blinded.
Your spell most likely worked properly, and he probably doesn't have any immunities.
IIRC, the Blinded status gives a 50% melee miss-chance and prevents ranged attacks, while Deafened gives a 20% miscast chance for verbal spells.
Neither should outright prevent melee attacks or spellcasting, if that was the question.
[Addendum] Here's the Wikia source on said statuses:
https://nwn2.fandom.com/wiki/Blinded
https://nwn2.fandom.com/wiki/Deafened