Grid not showing on imported PDF

Rhino Rhino for Windows
1

I have imported a PDF and it seems to turn off the grid in the viewports although everything is checked in Properties. I am using version 5 SR12

2

F7 doesn’t work to turn the Grid back on? --Mitch

3

Nope

4

Maybe the imported objects are far away from the grid location?
Or very large so the grid is tiny?

-Willem