We have a multisite environment. WP 4.8.9, Latest ACF PRO 5.7.2 on SiteGround with Dynamic (Object Cache) enabled. We stopped being able to add any fields. After hitting Update/Save, the newly added fields simply disappear. However when looking at the list of Field Groups, the Field Group shows there’s a number of fields added. But once you open a Field Group, no fields show up. Just blank field group. Please help this is a huge problem. thank you.
discovered that this is a an issue with Object Caching. SiteGround’s memecache Plugin called SG Optimize places a file object-cache.php into wp-content folder. After I disable Dynamic Caching in cpanel AND delete the above-mentioned file, the ACF Pro functionality returns to normal. But this is a huge issue, as we definitely need Object Caching on our site