Thanks John, that did the trick!
Thanks for the quick response.
To clarify more my doubt, here I attach a dump of my postmeta DB:

When I try to update the POST field=field_5628165af3668 with:
update_field('field_5628165af3668','777',$postid);
It doesn’t add the values on the DB as it does when I select the option in the backend.
What I am doing wrong?
Thanks
The themes are identical, now in terms of set up, as far as I can see they are identical as well, I checked for that option and in both cases it is unchecked.