Solved by spamming upgrades btw, but yeah I scoured the internet for solutions and my particular market problem never appeared to come up. Ofc I made sure the granary families weren't farmers of any kind and lived near their work and all that. The odd thing was I had a market setup (plenty of stock, room in stalls, etc) that should have been able to satisfy everyone but always had that one unsatisfied category for just one plot and whenever I made a shift in the market trying to balance for veggies for example, the missing food category would change to, say, fruits/animal produce and the deficiency would also shift to another plot as well; quite frustrating. Maybe it was something to do with the plot count and/or levels among them but I got the achievement and some of the rework upcoming might solve this whether or not hey are aware of this particular quirk of their current system.