Hi,
I have built 2 temporary shelters, each next to a deep sand mine.
Miners ignore the shelter next to their mine to go to another shelter way farther than the one they’ve got, as you can see in this video: https://youtu.be/46_8rYT0D-U
The shelter they ignore was built first (at least a year before) I’m not sure if they used it once, you can even see at the beginning of the video a miner passing in front of the empty shelter to go to the other one farther, so I think it’s a bug.