Can't get the value of Phone Number Input (thebdk) in backend

Hello,
I use the Phone Number Input plugin of @gaurav .
I have a trouble with this plugin.
I only can get the value in one backend workflow but not in another one.
I can’t explain the behaviour.
Could you please help ?
Many thanks,
Cédric

It was certainly a mistake of mine passing de data.
I solved it but didn’t understand yet why it didn’t work.