lockstep
Prince
On the topic of bugs, I found Salt and Ivory spawning in Grasslands. Civilopedia isn't saying they're supposed to spawn there. Considering that Ivory is normally only supposed to spawn in plains, and salt is normally reserved for low-food plots, this seems like a bug.
I've seen Salt on Grassland forests (like in your example) occasionally before the beta patch. According to Barathor (author of the "More Luxuries" mod), grassland is on the quaternary (priority 4) list for Salt, so this may work as intended.