i think i have some kind of bug

hello.
i have build second smelter recently and it brakes over time but the first one is perfectly fine. firs i thought that its coal clamps near by but ive moved them 2 metres away (Squares) still getting damaged over time...
i have build second smelter recently and it brakes over time but the first one is perfectly fine. firs i thought that its coal clamps near by but ive moved them 2 metres away (Squares) still getting damaged over time...