is rewritten to
d.description && document.createElement("P").appendChild(d.description);
which causes an javascript error
Uncaught TypeError: Failed to execute 'appendChild' on 'Node': parameter 1 is not of type 'Node'.
at nA.Za (apiv3.js:881:260)
at fv.c (apiv3.js:49:350)
at cd.b (apiv3.js:52:211)
at fv.gv (apiv3.js:627:214)
at a.c.handleEvent (apiv3.js:879:161)
at l.Ti (apiv3.js:131:417)
at he.c (apiv3.js:49:350)
at cd.b (apiv3.js:52:211)
at he. (apiv3.js:73:887)
As far as I understand the if https://github.com/Geoportail-Luxembourg/geoportailv3/blob/ddf2a349f6f46840379847adb0fa675bda420545/geoportal/jsapi/src/mymap.js#L304
is rewritten to
d.description && document.createElement("P").appendChild(d.description);
which causes an javascript error
The original code should however work …
(Same problem exists in apiv4)