As per title, if I load the viewer, then try to change the basemap, it will not change away from Mapillary Streets. If I leave the choice at, say, OpenStreetMap, then reload the page, the website hangs up at loading, but does pop up the basemap button. Choosing Mapillary Streets and reloading fixes it.
Also, Mapillary Streets seems to have had an update; the road ref numbers look awkward.