A freind of mine has the same issue, and contacted the Garmin support.
They told her that there is right now a problem with a certain type of HTC phone, that they aware of it and that they try to fix it in cooperation with HTC.
(That was in the end November/beginning of December)
So right now there is no fix for that.
You can either upload your activities via cable to your PC, or you install Garmin Connect on another cell phone to snychronise it.
Either it just a coincidence that you´re both using a HTC and it is something totally different
or the problem is slowly spreading.
You should check if synching via cable is also syncronising the fitnesstracker values (steps/HR/etc.) or just the activities. Im not 100% sure if it does that.
My watch is doing weird things too. It went back to facory mode (enlish instead of my own language) + my GPS doesnt work + when i try to use a workout through calander it went back to watch mode. I think it has to do with the new small update on Garmin express.
Oh yea! I cant Synch even with the cable on my PC.
What i ment was: first i had to turn off my watch and then turn on again. After that the menu was back to my language and everything worked again. Even my Phone. I did turn off and on my Phone also, but i dunno if that would have helped.
Sometimes smartphones ( and watches) need to reboot (turnoff and on) to work again. iI havnt done that once before.
I have a galaxy S8 and i have the same issue... sometime it works fine for some day and than, sync, suddenly stops to work... sometimes a reboot helps sometimes does not...
