I've been using my S5 Max for over a month, and have had four maps defined. In the last few days, the option to change maps from the main screen has disappeared.
If I go into Map Manage, one or two of my maps appears but the others say "Failed to retrieve maps". If I retry several times, they will eventually load. I then must restore the map that I want to use. But I have to repeat this process every time I want to vacuum a different floor.