Have you tried removing your featured image by editing your post?
Could it simply be a cache issue? I find that pages often don’t refresh correctly if only an “element” of the page is changed, especially with some fast cache plugins.. Try forcing a refresh by adding a parameter to the end of the string i.e. add something like ?x=1 which will force a full page refresh. Alternatively clear your browser cache.
Perfect @chanceduponthis and @hyperbytes. I tried to do the two things that you suggested to me and, at first, nothing it happened. Then I tried to open the site with Microsoft Edge (I use Chrome) and was all good. Right after, after deleting the cache of Chrome, all good also with this browser. Fantastic. Many thanks guys.
Ciao
Marco
