Same exact issue happened to me today on all 3 of my ovens, after updating to 2.0.4.
It worked in 2.0.3 - quit the game and updated (made no changes in config or in world), booted back up, didn't work (again no change in config or in world prior)
If DKAleX is already reporting the bug, I'll wait for an update on the issue, but just wanted to verify that this is definitely not a one-guy issue.