That’s a bug in Wikimedia’s geoline service. [1] As a workaround, you can still query for one of these relations, convert it to GeoJSON, and upload it to Commons. The AARoads Wiki (a fork of Wikipedia) has a decent tutorial for creating these maps [2], although Wikimedia’s Kartographer extension is a bit pickier when it comes to bounding boxes: 

[1] https://phabricator.wikimedia.org/T156433
[2] https://wiki.aaroads.com/wiki/AARoads:Maps/Creating_a_GeoJSON_file_from_OpenStreetMap