Not sure on your setup but GetOwner() doesn’t look like it will return a reference to the Reward Spawn Point here so your cast will fail. You can easily check with a printstring on the cast fail and check what getowner gives you.
If is the case, it looks like you need a reference to the spawnpoint… maybe using GetActorsOfClass or by setting a variable beforehand. Depends on your needs.
IMHO the cost of the casts here are negligible.