Instigator code changed in 4.11?

Seems there’s been some changes in 4.11 to the instigator code. In 4.10 when I spawned an object I never set the ‘instigator’ input on the spawn node and it used to default the spawned objects instigator variable to the object that spawned it, which made perfect sense to me.

In 4.11 it seems I have to set the instigator now otherwise the spawned objects instigator variable is null? Took me a while to track down what had caused my project to go from working fine to totally screwed as can be seen from these rather confused AI all having a group huddle.

Anyone else run into this problem after updating to 4.11?