Conditions to reproduce:
• full inventory
• targeter must be taken from the hotbar
• targeted place must be in the player's reach_distance (tergeter looks more bright)
I've got the same issue in my Teleportation mod, when using Jump Targeter (it's realized exactly like your targeter). This bug lives since 0.13 (AFAIR). If you use the device from the inventory - works just fine, but if from the hotbar - it disappears.
