Thanks for the reply. I mean that it works when I add it to post or page, but when I change ‘page’ (or ‘post’) to ‘link’ when I add the meta box, nothing is saved, and my input comes back blank when I go to the link form again, when I should have the link of my image. The data isn’t saved in the database either and I have no idea why.
I’ll look into _transition_post_status, thanks