Animation Blueprint IK Rig not working

I’m new to unreal from unity and don’t quite understand blueprints yet. I’m trying to set up IK feet on a mixamo character whilst trying to learn unreal at the same time.

I mainly followed this Tutorial
I’ve downloaded a mixamo character then using Mixamo Converter I added a root bone as this seems important for foot IK, I then set up a Full Body IK with foot, hand and hip goals.
I then set up a basic animation blueprint from this Tutorial and then added the IK rig and just for testing I’ve set it up with a default vector with one foot raised which looks fine in preview but when I press play the foot is on the ground. I’m new to Unreal from Unity and I tried looking for an Item in the Outliner that contained my ‘TestVector’ vector but can’t seem to find anything.
The main question I’m asking is why my preview is different from game?
I would appreciate any general knowledge as well.