Is it only a display issue or can the yields be confirmed as applying to the city?
I didn't work it out TBH.
Those cities are benefiting from Apocalypse mode
hyperyields, so have crazy food and production.
But if you like, here is my earlier save.
(This is a play test of one my maps Scrambled North America, which you will find in Downloads, or Steam. Just FYI cos you don't actually need the mod, b'cos the map has already been generated).
So to test it out:
1. Settle Alaska and rewild like in screen 2.
2. Blaze forest with Soothsayers, to cause sea level rise.
3. Beeline Conservationism.
4. Use Liang (who already has Reinforced Materials) to prevent the fires in the city and build a national park like in screen 2.
5. When sea level rises in ~100 turns, you can check.