Found a bug, pretty game breaking too during the interwar period (Mass Production era specifically). Not sure when, but at some point I noticed that I had gone from having an absolutely vast reserve of Kerosene and Oil resources to suddenly having over -100 of each.
When I look at the production stats for resources, in green it says for Kerosene -84 total, 25 used. Oil is at -3 total, 41 used. I noticed that every turn I was getting messages about city states losing access to oil and kerosene, and this was causing the amount to increase by -6 per turn, per city state and that the game was not counting any of my own production either.
Haven't reached an upgrade tech for Oil or Kerosene units since spotting this, so I'll have to let you know if it's actually a real bug or just the game incorrectly displaying an amount while still reading the actual count based on whether or not I can upgrade my units, but as it stands this is almost game-halting as every turn the game is digging the player into a deeper and deeper hole. Deleting consuming units doesn't seem to fix it either.
Also getting the same UI graphic bugs as above despite having GPU decode turned off.
Edit: Just tried upgrading a Great War Bomber to a B-17, confirmed no dice. Game does indeed believe that I somehow am producing a negative quantity of resources and is further compounding it via city states.
Edit 2: Deleted -all- Kerosene and Oil consuming units. Brought me down to -10 Oil and -97 Kerosene. Within 3 turns I was back up to -23 Oil and -120 Kerosene.