App Overwriting Device

[Javelk]

When I sync my Versa 4 to the FitBit App the app overwrites all the progress between the times it synced.

[JuanFitbit]

@Javelk , A warm welcome to the Community! Thank you for your message and efforts.

Please on the Fitbit app tap on the devices icon (upper left corner).
You'll see the list of the  devices paired to your account.

Make sure that MobileTrack (Smart device/Mobile Device ) option is not listed there. 
If you see it, tap on it and remove it from your account. 

This feature uses the sensors on your phone to count steps, and was designed to be used, when you don bring your Fitbit with you. (eg. left the watch at home charging, forgot it on the desk, etc)
If you use MobileTrack and a Fitbit (Versa4 ) the steps recorded with the tracker could be overwritten or added from/to the ones registered by your phone. 

It's important only to use 1 method to record the steps at a time.