Level load working correctly in editor preview but not on iOS device

Thanks for your reply Rudy, I am on 4.5.1 (launcher) and have just tried a few more tests - I started a new project and created 3 new levels, each with a UMG widget - Level 1 links to 2, Level 2 to 3 and Level 3 back to 1 with a button on each. Again, in editor this works as expected (the next map is loaded on button press) but not so on mobile.

What I have now noticed is that on device whenever I call Open Level the default map from the project settings is loaded. So whenever I call any Open Level at all, it ignores the level I am asking it to open and just opens the default map - this indicates to me that perhaps it cannot find that level? Are all maps bundled with an iOS deploy by default?