on for example firewood splitter, if you have production limits in place, when the lower limit is hit, only 1 firewood splitter is unpaused, the rest remains paused.
I guess its just not traversing the list of buildings properly when unpausing.
Same happens with Iron Mine. I have to demolish/rebuild the building (in case of mines) or move hte building (in case of firewood splitter) to make them work again