That is odd behavior. Once I have time to access the Lab Computers with UE4, it should be an easy fix (maybe tonight, no promises ;)). Nice Caustics BTW!
Oh and a good piece of information about turnFrequency: it is the number of seconds before the leader generates a new seek target vector coordinate. In human, that means they will wait however long turnFrequency is set to before turning (looping). The lower turnFrequency is set to, the more they turn (It does seem a little backwards).
I thought maybe was due to turnFrequency, but it is not the case, since you had your value set low. My best guess at time is he is fleeing from something (maybe your player haha… (default behavior is to flee from player at the moment XD))
Cheers,