Sorry to dig this one up again and I understand you think it's easy but not for me!.....
I have a twin controller set-up and the master has cached maps turned on, I've scrolled around the area I intend to fly and when I get to the site and open the app..... no map!.... at all, just greyed out boxes....... but the slave does have the maps and I haven't even scrolled that one around (although we are working within a mile or so of home?.....) last time out though I decided to check the slave and the "cached map" is OFF!......... am I right in then believing that after scrolling around to cache the map you have to turn it off?......... confused!....