We understand that you are experiencing an issue in that the Title/Meta Description you have specified in the plugin settings is not displaying as expected in the search results for your site.
We checked on the page https://www.itineriamo.com/itinerario-cuba-e-florida-on-the-road/ and did confirm that Yoast is outputting the following title and meta description in the source code (see image here):
<title>Itinerario di viaggio: Cuba e Florida on the road | Itineriamo.com</title><meta name="description" content="Un itinerario di viaggio alla scoperta di Cuba e della Florida. Prima parte all'insegna delle tradizioni cubane, seconda parte on the road in Florida..." />
Can you please confirm whether this matches what you have specified for the Title/Meta Description in the snippet editor settings in the plugin?
Also, please note that whereas Google typically uses the Title/Meta Description from the metadata for indexing, this is not always the case. Google will sometimes modify these as it sees fit, as well as sometimes adding the brand or sitename to the end of your title. This is not due to the plugin not functioning as expected, but rather is due to Google modifying the Title/Meta Description it indexes as it’s algorithm has concluded that there is a better version to index.
We also have additional information on this topic available at the following links: https://yoast.com/google-page-title/ | https://kb.yoast.com/kb/google-shows-different-titles-for-my-site/ | https://kb.yoast.com/kb/my-meta-descriptions-arent-showing-up-in-the-search-result-pages/.
Please refer to these articles as the include recommendations for crafting a page title/meta description which will help increase the likelihood that Google will use the value you specified instead of modifying it as it sees fit.
