As described on github, there seems to be an issue in Leaflet 1.4.0 when displaying multiple maps on a same page: base layers aren't properly selected. In Leaflet 0.7.2 however, this seemed to work fine.
The following fiddles demonstrate the issue: Leaflet 0.7.2 http://jsfiddle.net/sc28/fvy8aq37/2/ --> the base layers are correctly selected in both map controls Leaflet 1.4.0 http://jsfiddle.net/sc28/9j3hstgx/ --> the base layers are only selected in the second map; when a base map is clicked in either map control, it gets deselected in the other.
Does anyone know of a solution or workaround for this issue?