Sync and calendar issues

Hi All, first post here. I have an edge 520, couple of years now and recently it has trouble uploading to my phone, sometimes I have to go back later and turn the edge 520 on and wait a few minutes and then it will upload to my phone. Now it won't sync to strava and we know if its not on strava it didn't happen. But looking today on my phone through the Garmin Connect app there is nothing in my calendar for the last 3 months, yet the rides are on the edge 520 and strava (except for yesterday). I have updated everything, un-installed and re-installed all apps and still nothing happening. Im at a loss to work out whats going on. Thanks