The template player pawn has a variable called TeleportProjectPointToNavigationQueryExtent that sets how far away from the hit position it will look for valid teleport spots. Setting it to a small value should make it not teleport through things.
Another thing you can do is disabling the teleport when the controller is angled up more than 45 degrees or so. This makes the teleporting more ergonomic as well, since disabling it makes the teleport easier to cancel one you pushed the button in, and the indirect targeting makes it more difficult to aim.