On the 6th, iOS App was working on my iPad, but after the update this morning, March 8th, the background appears with the music, but no login prompt, and therefore no way to select route, etc. and start riding.
Its working fine for me. Have you restarted your iPad?
In addition to Steve’s comment, try rebooting the router too.
Restarting the iPad fixed the problem. Thanks to you both for your comments.