Just ran a couple of time is money challenges and the kobolds are ignoring teleporters and also D Doors after they have picked up a crystal. They will use them to get from the start zone to where you have placed the teleporter (in a circle of power) but then will not use them again even if the crystal is close to the teleporter. (occasionally before they would run back rather than use one if you had a long line of torches for example)
Anyone else having this?
Buying time is also doing the same.