Difference between steps on Sense 2 and steps reported in app after syncing

[EllieDeePee]

My sense 2 has recorded 16,411 steps but when I synced just now it is reporting 12,671 steps in the app (iOS latest version of both app and system). I saw a similar post where the explanation is that the app just hasn’t updated yet however this does not apply to my situation. I have been out all day and I only sync my device with my iPad; this was the one and only sync I performed today.  There are also no active zone minutes showing in the app and 146 in the watch for today. 
There are zero floors showing in the app and 81 on the watch. 
The calorie count in the app is 1600 - only 300 over my BMR despite 6 hours of activity including climbing hills, steps etc. 

I’m used to the sleep data not updating until I jump through hoops by adding a manual score but this is a spectacular sync fail. Can anybody advise on this please. Please note that I have checked for updates etc etc. 

[EllieDeePee]

Further information - I note that this tab is suggesting that I haven’t synced at all today and that my battery is low. It evidently isn’t updating this data correctly as I’ve synced twice now and the watch was charged fully as of this morning and is still showing 82%  synced again and it’s added another 2k steps but still not what is recorded on the watch and still no AZ data. 

[Guy_]

Hi @EllieDeePee - in the Fitbit App, device page (Connected to) do you by any chance have your iPad connected to your account, if so remove it?

As you have a Sense I've moved your post to that forum.

[EllieDeePee]

Hi Guy, thanks for replying. Why would I want to remove my iPad as the device I connect to since it IS the device I connect to? Also, I have a Sense 2 not a Sense (see title and body of post) and you seem to have moved my post to the latter. 

Ellie

[Guy_]

Thanks, @EllieDeePee - the screenshot provided shows a Sense not a Sense 2, it's why it was moved, it is moved back now.

You only need your Sense 2 attached to your Fitbit account to measure steps etc., and if the iPad is also attached it should be removed.

It has got nothing to do with the connections and login, as of course you watch must connect to the phone and the Fitbit App, and you must be able to login to the Fitbit App to upload the watch data, but you don't need normally to collect data from the iPad if it can.

[EllieDeePee]

I don’t know why it shows as Sense rather than Sense 2 but it is definitely a Sense 2. I have no other devices attached to the account. I synchronise my data with iPad Air 5th gen. Eventually the step count reached the numbers on the watch but achieved this over several synchronisations.  Today I am trying to reconnect the Sense 2 after removing it from the Fitbit app and using Forget this Device on my iPad. So far no luck.