I have found an error while trying toggle visibility of some MapImageLayers in Experience Builder v1.1 (works just fine in v1.0).
The error says "Uncaught TypeError: Cannot read property 'parentJimuLayerViewId' of undefined", and it "kills" the map.
You can try it for your self here: app. Try toggle visibility of "World Traffic Service" layer.
Thanks in advance, Matěj.