I can no longer edit AND save the duration of an exercise

[Seb1000]

I track my weight training in another app, but want to have it in the Fitbit App, too.
My modus operandi is:

- start Fitbit Watch App with weight exercise, wait a few seconds
- start other Watch App with weight exercise (Fitbit Watch app will then stop)
- complete my training
- sync all to Android mobile phone
- edit the duration of the exercise in Fitbit App

... the Fitbit App accepts my edit, in the next screen I see the activity with the edited duration, but a second later, it reverts to the old value again.

I tried manually syncing multiple times and shutting off Bluetooth on the phone. 

[Rich_Laue]

Yes, as others have mentioned, the edit function on android is not working.