Created Maps have a bold orange grid overlaid...No idea why.

Sorry if I missed a discussion on this, but I searched through about 20 pages of posts and nothing covered this question that I saw. I haven't created any maps for quite a while, so I don't know if this is something I figured out last time I made maps or if this is something from an update since then. I converted my .pdf maps to .pngs and scaled them as I wanted them. I then created a map from a file and set then aligned the d20Pro grid. When the map opens, though, there's an additional grid overlaid on top of my map. This additional grid is in bold orange lines, and I can't find any way to shut it off or even to explain why it's there. The grid I placed during map creation is there, too, as I intended it to be. For reference, the bold orange grid is double the size of the grid I set up for the map. No matter how I size the map, the grid is always the same (for each individual map).

Am I missing something simple, here? Is it only visible in that view, or will it be there when I broadcast the map to my players? I've tried this on about a dozen different maps and they all do the same thing.