I seem to have the same problem with downloading a route a created into my Wahoo Elemnt. I used to be able to do it but not anymore. I managed to go as far as step No 1, but once I gave the route a name and clicked ok , nothing happened - the route would not save. Any idea what I'm doing wrong? As I said I managed successfully download routes into my Wahoo in the past so the issue is quite recent.
After you've given it a name (when it says "Import FIT Course File") and then clicked OK, the route should be listed under the Routes section in the ELEMNT app. It's working OK for us here, so you may need to contact Wahoo to find out why routes aren't importing on your device.
As report in another topic, this is still an issue. I do not believe it to be a Wahoo issue, but an Android issue.
Please see the following post for updates on this issue: https://www.plotaroute.com/posts/2613/D/1