My Garmin Forerunner 55 has suddenly stopped syncing to Runkeeper. I've had it about 2 months and all activities up until yesterday sync'd almost immediately with no problem. I've been searching around and it seems like it happens to people sporadically (going back at least 5 years from what I can tell). But I've yet to see an explanation for why it happens or how to fix it. I've connected them together in BOTH Runkeeper and Garmin apps as well as on the web based platform. I've even deleted and re-installed the Runkeeper app with no joy. Any suggestions?