Leaflet configuration issue on installation

Steps to reproduce

• Install application version 1.1-SNAPSHOT on a local XWiki 11.5 via the XWiki Extension Manager (after making sure that the previous local installations were cleaned up from the permanent directory extensions repository).
• Go to a point entry listed on the home page of the app, for instance "Maps/Demo/Mountains/Broad Peak"

Result

The map on the point page does not show up and the JavaScript console displays the following error:

The script from “http://ako:8090/xwiki/webjars/wiki%3Aabraca/leaflet/1.5.1/1.5.1/dist/leaflet.js?r=1” was loaded even though its MIME type (“text/html”) is not a valid JavaScript MIME type.
Broad Peak
Loading failed for the <script> with source “http://ako:8090/xwiki/webjars/wiki%3Aabraca/leaflet/1.5.1/1.5.1/dist/leaflet.js?r=1”. Broad Peak:1:1
Error: Script error for "leaflet"
http://requirejs.org/docs/errors.html#scripterror

When removing the version number "1.5.1" from the JavaScript extension in LeafletUtils (code below), the error is not raised any more, however the map does not load correctly, possibly a CSS issue.

'leaflet': ['$services.webjars.url("leaflet", "1.5.1/dist/leaflet.js")'] 

Map: