Stone keeps disappearing
My home city is losing stone every time I do a battle or "view" one of my armies.
I've turned the alchemy lab off, and I can't see any reason for this to happen. I'm also quite far from reaching the resource cap, so that's not it either, and there is no building going on. And besides, if it was "normal decay" it wouldn't only happen whilst I'm doing missions.
It's quite an annoyance having to keep adding stone to the city (for ammunition to the bolt throwers in case of a siege), so please fix this bug.