

This is a modded resource. Hovering the mouse on the resource, in the map, change the visibility of resource patchs, some resource patch appear.
I look many times the definition of this resources and I don't think this is the problem:
https://pastebin.com/Wd9Szxih
Is (almost) identical with the definition of crude oil, and the sprite priority is on "extra high", so should be not a problem of z-axis.