triathlon activity on 735XT not synched

Hi,

I have done a triathlon yesterday using my 735XT but I tried to upload it via Garmin connect and it's not appearing. This activity is well recorded on the watch. There are no error messages. I tried to reboot it, I tried to disconnect and reconnect it, none of those are working. Do you have any thoughts about how to sort this out? 

Thanks a lot

Mehdi