Theres no amount left to download, no %. i also got a message saying all maps had downloaded. If i leave it on wifi only, all is fine but again when i switch to offline/plane mode, its blank close up.
However if i then switch back out if plane mode and back to wifi, i get downloading but no % showing again for switzerland which i happen to be looking at. On wifi i can see details.
Just tried it with uk and same thing, says its downloading when i enter the map even though it appeared to download fully yesterday.
I’ve got an iphone 6plus if that helps.