CraftBook version: CraftBook5 v5.0.0-SNAPSHOT;4704-2fd8bbb
Paper version: Paper version git-Paper-576 (MC: 1.16.5) (Implementing API version 1.16.5-R0.1-SNAPSHOT)

CB5 Mechanic bug: Better Ai causes mobs using 'attack passive' to not attack players
Replicatible by using the default config and spawning a zombie in survival mode
After removing the line (and leaving just a '-' so it doesn't regenerate) I reloaded the mechanic and zombies started pathing towards players again.

I've made a change that'll make it more reliable. Due to limitations in the Paper API, there's no way to guarantee this to ever be the case. However, it should generally be okay now.