The website is adding the content of the waypoint input as name.
So if there are coordinates, coordinates are put in the file. If there are names from geocoding results for example, they are put in there.
This behavior makes sense, because the website will show the same content in the input boxes that you had when planning the route.
It’s a bit unfortunate that this seems incompatible with the app now. I can check if the website could not set the name property, if there are only coordinates set in the waypoint list. But this won’t change the existing .kurviger files.