Weeeeell, first I would suggest you use [AI Behaviour Trees][1]. But that’s not really the solution to your problem, just a general recommendation.
Your problem is, that immediately after the move to was successful, it is triggered again. The “In range” does not seem to be set to false again (ever). But even when you would, it would be set to true immediately again, because the AI is still standing right next to you.
I guess what you want is some kind of cooldown. Maybe introduce a variable “last touched” which you set to the current upon touching you. You could then check this variable and make sure that the AI does not start chasing you again before some has passed
https://docs.unrealengine.com/latest/INT/Gameplay/AI/index.html
[2]: https://docs.unrealengine.com/latest/INT/Gameplay/HowTo/UseTimers/Blueprints/index.html