Dear Olga,
the problem you detect is not related to the failure to load the slider but it’s a carousel that we are setting, as the site is under construction.
I confirm the same things said by the user below, used multiple browsers (safari, firefox, chrome, edge), we use a plugin to speed up and optimize the loading of data (WP Fastest Cache) and the problem was found when (as already said by the user) we have updated WordPress + XStore to the latest versions.
Of course we have already tried to clear the cache and the browsing history.
We also tried to disable all plugins, the problem remains and occurs at times. An interesting thing is that after it shows up, it stays for that page.