Schrödingers (in)valid character

Good morning everyone,

I made a simple interface-based interaction system and an actor, that should teleport the player when interacted with.
I can teleport various other actors when I interact with the teleporter, but not the player. The teleporter tells me, that the Player is not valid.
But the Interaction-System inside the Character Blueprint tells me, that the player is valid.
As you can see, the Interaction sends a self reference of the player character to the interacted Blueprint. So when the reference on the player side is valid, how can the reference be invalid on the object side?
Help would be much appreciated, as I am mighty confused.

Thanks for the help and have a nice day :smiley: