iOS App Increasing Steps By Huge Amounts?

[Merwex]

My Charge 5 seems to record my step count and mileages accurately - however when I synchronise with the Fitbit App on iOS it can, occasionally, double the step count, or in one case increase it by a factor of 100!  This seems to occur randomly.  My Fitbit firmware is up to date, my app version is up to date and I’m running the latest version of iOS on my iPhone 13.  Does anyone else have this issue - and if so how do you fix it? 

[JuanFitbit]

@Merwex , A warm welcome to the Community! Thank you for your message. 

It appears that you have MobileTrack on.

This feature uses the phone's sensors to count steps. This is for when you have left your Fitbit at home (e.g. while charging). Please make sure MobileTrack is not activated.
It may happen that the steps recorded with the cell phone overwrite those of the Charge 5.

In the Fitbit app, tap the devices icon (top left corner).
There you will see the devices linked to your account.
If you see the Mobile Device Active option, tap it and remove it from the account.