Buddypress Metakey fields not updating

Hello,
– In my profile fields i have some fields lets take for exemple “Occupation”
– I Installed ERF and created a form then some fields but when i use metakey of my previeous occupation field in Map to usermeta.there is no synchronisation.
I have seen the tuto with advanced custom fields and i understand how it works but i cant recreate fields again, i have users with the previous fields i mentionned i cant restart again with all fields.
I Just want to sync the new field created with new register form with the fields that i already have. (I am using buddyboss which is a fork of buddypress)
I Already used all the possible metakeys, for exemple for occupation field
’35’, ’14’, ‘field’, ‘alternate_name’, ‘occupation’,’field_14′,’field_14-1′,’field_14-3′,’field_occupation’
Those informations were fetched from my site and my database.