Upgrade craziness

I went through and upgraded my bread chain. Since I had a ton of flour floating around, I did the bakeries first, then did a majority of my mills, and did incremental upgrades on the rest to try to balance out the amount of flour vs the bakers needs. I got down to the last mill, production showed me to be -16 short on flour per 12hr with the rest of my mills and bakers being lvl 5 and only 1 mill remaining at lvl 3. I upgraded the last mill to lvl 4, and the production chart now had me around 300 short per 12hr. Thinking it was a glitch and that it was due to needing to be refreshed, I upgraded the mill to lvl 5. When I logged on a few hours later, the number was back at -16. So I didn't fret about it. Now that the last mill completed upgrades earlier today, I looked at the chart and it now has me at -503!!!! So I upgraded my mill to make production worse? Other then the upgrade, nothing had changed on the remaining mills and bakeries. And it isn't due to running short on wheat as almost all my farms are at lvl 5 and I have a 3k overproduction due to not upgrading the stables yet.

Were you checking the values *during* upgrade process? Because the economy calculator isnt accurate while buildings are being upgraded.

Actually no, I checked the value before I started the upgrade and after. Wasn't concerned about value when it was upgrading as I kept track on inventory (if I needed more) and not production.