I thought this was fixed as I haven't experienced it in a good while.
As title says - running a base in debug for testing, noticed some of my mealwoods were stifled - checked temp overlay :/ Centred on the mechanized airlocks.
**Edit** Just loaded my stream colony, and the same thing has occurred there. see pic below.
Steps to Reproduce
Build 4x airlocks in a row and wait - regular dupe traffic will help.
This issue has not been confirmed by a developer yet.