smelter and charcoal kiln bugged?

[Arcadefire]

my newly placed smelter and charcoal kiln keep pausing and starting up again whenever they get used. I don't know if this is actually a bug or some building issue I caused.

[avatar.zero]

Are they covered by anything? Smelters and kilns are smoke-producers just like campfires and follow the same rules (going out during rain, stoppinig and restarting if they can't dissipate smoke fast enough, etc).

[FissionChips]

I haven't seen smelters & kilns affected by rain, but they will definitely be choked by smoke build up - it might not be obvious, the vent could just be too close to something, or it might not seem like much smoke is building up but it's enough.