I am trying to save this print composer as PNG
When I open the saved file, this is the result
The same thing happens if I save to pdf. Any idea what's going on?
The composer map windows don't automatically refresh when you update layers, but pull the latest view when you export. If you toggled each layer then added the map to canvas this could cause the problem described. If you refresh the canvas, does it change to look like the .png?
If so, toggle each layer as before, refresh the canvas and then lock the layers in for the corresponding map in the composer. This should then remain the same when you toggle a new layer and refresh. Once this is done for all layers, the image should export as expected.