Duplicants are stuck trying to deliver construction resources, but cannot reach the area due to the locked door. So they are just standing at the door, not moving. They do have the ability to go the other direction and complete other tasks, but are stuck trying to reach this one. Save file should have 2-3 duplicants exhibit this behavior upon load.
Build the layout shown in the screenshot and captured in the save file. Watch duplicants try to reach a place they cannot. Thanks! :)