If this is ON your VRPawn, you’re just telling the whiteboard variable to set itself as itself. Unfortunately, this does nothing. 
You definitely want to take off the “Then 3” on tick- you don’t want to re-cast and re-set a variable actor on tick- I don’t know if it’s contributing to your problem (it could be), but it’s definitely bad news down the line and resource intensive doing it 60 times/second. Just take the beginplay line off tick.
Additionally, add a printstring to “CastFailed” on the cast to VRPawn. Because if the cast fails, we know it isn’t getting through, so you know for sure that the Hunger Whiteboard variable isn’t being set.
I am thinking that is what is happening on the Overlap code for (FoodEat_Box) - I think the cast is failing and so it isn’t continuing to the “IncreaseHunger” function, so the reference isn’t called, so there’s no error.
Look into that and let us know what you find out!