This is driving me nuts - Collision

Well it’s hard to guess without being able to take a look “under the hood” but have you tried enabling Simulation Generates Hit Events (and/or overlap events, depending on what collision event you are looking for) in the collision settings?
Also make sure the appropriate collision channels are set to block if you haven’t already.

If you still can’t get anything to work then you should upload an example project or something we can look at.