Whether in mines or under the roofs of houses, if you place an item too high up, the hearthlings will be unable to take it back down again. The expected behaviour is for them to be able to take down anything you ask them to undeploy, regardless of proximity to roofs.
I created a test scenario to highlight this:
Create a cave and place wall lanterns at varying heights.
The hearthlings add them to the wall without a problem.
Order the hearthlings to undeploy the lanterns.
All the lower lanterns will be undeployed. The highest lantern will not be undeployed. The hearthlings all go idle showing they have no intent of doing anything with that lantern.
I’ve seen this issue with a variety of items, so it isn’t just wall lanterns, but the wall lanterns are the easiest to set up a “clean” experiment with outside of debugging tools.