Hi,
I believe that the problem is misconfiguration in metaboxes array.
Just to be sure you can try to enable ACF options panel with:
`add_filter(‘acf/settings/show_admin’, ‘__return_true’, 100);`
and try creating your fields with the Visual tool of ACF, if you still experience the same problems then indeed is something with the server configuration, if everything is saved correctly then you are doing something wrong in acf-metaboxes.php