Hello Fernando,
I see that your site is using a theme that has both mobile and desktop versions of the site. One of the menu divs has this class that makes indicates it is hidden by default on mobile:
class=”whb-row whb-top-bar whb-sticky-row whb-with-bg whb-without-border whb-color-light whb-flex-equal-sides whb-hidden-mobile”
This may be causing the problem. If this menu is cached in our dynamic cache and then requested from a desktop browser, the menu will not appear.
We have a setting in the WordPress admin >> SiteGround Optimizer >> Caching >>Browser-specific Caching. Toggling on this setting will create a separate cache for mobile and desktop users, and the problem should no longer occur. After toggling the feature, you must clear your website’s cache and Cloudflare’s cache.