Maybe this is intended, but it wasn't always this way:
Also on the left the water is instantly boiling again because the upper layer of the abyssalite is several hundred degrees. Wasn't that supposed to be fixed a few patches ago? I think I checked it and it worked briefly at one point (with there being a cool upper layer). Now it seems to be broken again.
Spawn any new map. Check swampy moon with the tungsten volcanoes and sap tree