I use an IPAD to enter this site. I can locate a memorial, call up the picture of the headstone then go to map for location. I am unable to get the map to full screen. The icon is located on a blue strip preventing it from going to full screen. When I press the icon, all it does is give me the label full screen. My IPAD uses iOS version 11.4
Don't click on full screen, click on the arrow. Full-screen is a label telling you what the arrows do.