Activity data seems to disappear - Inspire 2

[Cammei]

3 year old Fitbit Inspire 2. For a while now data seems inaccurate or missing. I swam a mile 3 days in a row in approximately the same time frame. Info tracked was wildly different all three days. Sometimes it picks up my swimming as an elliptical. Sometimes not at all. (I’m not manually setting the exercise for Swim) Today I worked out for an 1:15 in the gym, 45 minutes in the water, swam over an hour and manually set an 11 minute Run. Later I had to manually add some steps for earlier in the week. The only activity showing in the app today is the Run. For the last 3 days just the steps I added show in the app, the swimming has disappeared. Most of it, but not all, shows up in the Dashboard at Fitbit.com. Does only one activity show up in the app now? 

Moderator edit:  updated subject for clarity

[JuanFitbit]

@Cammei , 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 tracker at home charging, forgot it on the desk, etc)
If you use MobileTrack and a Fitbit (Inspire 2) 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.

[Cammei]

I don’t see anything like MobileTrack. Does only one completed activity show in the app now? I see more when I log into Fitbit.com. Every time the Fitbit app changes I like it less. It used to be simple to read and showed accurate data. Now it's convoluted and inaccurate. Not sure I'm going to upgrade to another Fitbit.