I think it’s pretty much the same result as in a video, which was posted before ( UE4 Portal Doors - YouTube ) expect mine works both ways… xD
And I did some tests… it really seems like the face the the portal is overlapping with an object (or it seems to be enough to even just be inside the “Bounding Box” of an object) is triggering the multiple teleport…
I don’t know much about that but it still happens when i set that object to BlockAll and untick Generate Overlap Event in the Collision-Tab. I could really need some help with that…