On the Edit page for a Listing only a single image is appearing where six have been added. The user has no way to know what images have been added or deleted without looking at the Details page for the Listing.
In addition, the number of images that can be added to a Listing appears to be unlimited even though the following code has been added to the function.php file through Code Snippets:
Please disable third-party plugins and customizations (if there are any) and check if this issue persists. If you use a caching plugin, make sure that caching is disabled for logged-in users.