in nffa_save_meta_box_tags()
, you use $mtags
, but $mtags
is not defined in that function. Manually replacing the two instances of $mtags['id']
with 'NFFA_meta_tags'
makes the value save – showing that’s part of the problem.
The other problem is that santize_text_field()
has a typo, should be sanitize_text_field()
.