Here’s my experience with my Suunto Race S:
Everything was working perfectly until this summer, when I started noticing that routes were disappearing from the watch, even though they appeared as active in the app. These were routes created exclusively within the app. It didn’t matter which routes or sport modes I used—they would just vanish.
After a while, and wondering what might have changed, I realized this issue started after I installed the maps for the Aquitaine region in France. So, I decided to uninstall them to see if that was the cause.
To my surprise, I found it impossible to uninstall that map. Damn! And the routes kept disappearing.
Then, I had the idea to reinstall the latest software version. That finally allowed me to uninstall the Aquitaine map. Since then, the routes have stayed synced on the watch!
Anyway, I don’t know if it was just a coincidence, or if the Aquitaine map actually had something to do with it (I installed the same map on my wife’s Race S, and nothing weird happened to hers), or if reinstalling the software fixed it. But the fact is, about ten days later, the watch seems to be working normally again (and I hope I don’t jinx it by saying this—phew).
Sorry for the long post. I hope this helps someone out.