I found the solution!
On sites created with WPBakery, if you export a site containing links to parts of the site inserted into the pages, you must add the strings in the Custom Find & Replace section like this:
FIND https%3A%2F%2Fwww.mementopet.it%2F REPLACE http%3A%2F%2Flocalhost%3A8888%2Fmementopet%2F