Grid shows instead of an offline map, help!
If you selected the downloaded offline map to be active and then on returning to the main map you see just the grid with labels and no map, like this:
Then it means that for the area or zoom currently shown on the map there are no tiles to show in the downloaded map. Either you have the map at the zoom level that is not inside the downloaded map data or area doesn’t match. Grid shown in such case gives you information on the current zoom level at which data are missing (Z(oom)=20 in the case above is missing). If you are sure that you downloaded the area that is being shown, then please just zoom in/out to get inside the zooms that were downloaded.
The advice would be to always download the map from zoom level 2 to the required higher level. Lower zoom tiles take very little space, but allow to find the downloaded area easily on the map by zooming out.
Whenever you use offline maps, label with the map name turns into a button:
Tap on this button and pick an option to focus into the downloaded area. Then you can just keep zooming in, keeping the downloaded area at the map center.