The killstreak turret does not auto-auth to players unless they are in a clan. Solo players are killed by their own /ks turret, so I have caught them running up to it and manually authing on it before it fully sets itself up. (clans work fine)
I do have 'Powerless Turrets' and 'DynamicCupShare' but those are the only two plugins I can forsee conflicting with auth.

Side note: is there a way to make the /ks heli auth to the player/clan as well?

I can send whatever info is needed and the plugin works great outside of that. No other issues.