410 Gone on Updating (save changes)

I recently moved the site from one server to another (same domain) and the forms, although they are working, I can’t make any changes to them, as it gives me a 410 gone error (wp-admin/admin.php resource is not available – but the file is there) on saving.

Things I’ve tried:
– Resetting .htaccess;
– Uninstalling WordFence;
– Reinstalling the plugin;
– Installing older versions.

Nothing worked. Any help would be very much appreciated.
Thanks in advance for your time.