Hi @raymondseger ,
Thanks a lot for reaching out and apologies for the delayed response.
On wp-admin, ACF saves the user ID as a string and that is why you get this: a:1:{i:0;s:1:”1″;} therefore you should pass a string array of user IDs in update_field(…) to obtain the same results as in wp_admin i.e. something like this: array(‘1’, ‘2’, ‘3’, …);
I hope this helps.
