Can't purge notifications from Android Phone, Charge 3

[HDW1946]

My Android phone has hundreds of saved notifications.  I have attempted to remove them by following instructions on page 21 of the user manual, but  without success.  I replaced the phone because it was so slow when using the Fitbit App. I have turned most of the notifications of (only 2 active), but I still have notifications dating back to a Charge 2 that I replaced with the Charge 3. 

Thanks for the help. 

[Lilbiddy]

Since all the latest fiascos and having to reinstall the app several times a years worth of notifications has appeared. I have never had them shown before and now I can't get rid of them. I am using app 3.4.1 as I am using an android 5 phone. Tracker is a charge 2 but this appears to be an app problem. 

I'm attaching first and last page screenshots.