Baldur's Gate : The Sword Coast Chronicles : NWN2 Persistent World

Question: If you lose Turn Undead with taking Cavalier Kit for Paladin, but gain it again with Cleric levels, does the build retain Turn Undead from that point on? And will it retain it if you continue to take Cavalier levels after gaining from Cleric?

No.

So Cavalier prohibits Turn Undead? As another way of saying it (over just loses Turn Undead).