This is a Large/Fractal map at around 1820 AD, with most of the world settled. The yield icons are showing incorrect values, but the tooltip is correct.

Leader Scene Quality: Medium
Overlay Detail: Low
Shadow Quality: Low
Fog of War Quality: Low
Terrain Detail Level: Low
Terrain Tessellation Level: Low
Terrain Shadow Quality: Low
Water Quality: Low
Texture Quality: Low

Specific places to look at are the plains and hills around Suo, Echizen, Fukushima and Bizen on the far eastern big island.



Change "Overlay Detail" to "Medium". No change in the issue.



Still testing to see if I can figure out what causes this, or whether it's corruption in the save file.

Even after rebooting and reloading the save files from scratch, the same errors appear. Including loading previous auto-saves.

The only thing that seems to work is at 3:30 in the video where I load an older save and re-expose the tiles hidden by fog of war.