We discovered a naughty bug that plagued the map performance.
Under some (hopefully) quite rare circumstances some routes happened to be duplicated over and over, and up to several dozen times for worst cases.
The consequences were not immediately visible, but this affected the routes and way points listings, and also it made the map page run very slowly.
This issue has been fixed tonight, feel free to report any unexpected behavior through the feedback service (middle right of the page).
Sorry for any inconveniences you might have suffered.