This was a puzzle to figure out, and I still don’t know why it’s happening.. but I know how to fix it.
The problem is somewhere between the distribution maps, and the surface replicators.
To get the grass to show up as intended,.. (See pics)
You need to select, and expand the (forest floor) group,.
then select the (Grass 1) replicator.
In the “Display” section, change it to show the “Bounding box” view,.. so that you can see what’s happening.
Then, in the top section,. you need to “Edit” the distribution shader settings.
In the shader editor,. select the second texture map in the Diffuse channel, and switch off (invert)
next, you need to edit the surface replicator,.
In the top right section of the replicator panel, there’s an option to “Use Shader” ..Switch this Off,.. then, wait a second or two,. and switch it back on again.
Follow the same process for the other grass replicator (Grass 2)
you should be good to go.
After you render to make sure it’s working, you can save that file back into the folder, as a new scene file.