Charge 5 won't sync with my iPhone without internet connection

[Victor142]

currently my charge 5 cannot sync with my phone without internet connection. So basically if you are traveling out side of your country the Fitbit device becomes mostly useless device if you don’t international data roaming. If this situation continue, this is my last Fitbit device. 

Moderator Edit: Clarified subject

[JohnnyRow · Accepted solution]

"sync" can have a few connotations.

Without the internet, some data can get from  your tracker to your phone. For instance, your phone can continue to display your current step count, calorie burn, etc. But a full "sync" requires updating the fitbit database, then coming back to your phone.  That requires the internet.  There is a finite amount of data that can be stored in your phone without going to the main database, before it will get lost, and that will happen if you are away from the internet for too long.

[Xoyo]

I understand that, but why can't I even sync the clock when travelling and no internet? This for me is a frequent problem. Surely your explanation of data storage doesn't apply here.