Hidden navigation on a page (bug?)

Good morning,
I have css code to change the color on hover.
It works on all pages but on one page the navigation is hidden and is seen only on hover.
Video attach.
This is the code I have now:

/* Nav item color */
.header-nav-item a {
    color: 414241 !important; 
}
/* Nav item hover color */
.header-nav-item a:hover {
    color: #FF7F8E !important;
}
/* Nav item active color */
.header-nav-item--active a {
    color: #FF7F8E !important;
}

/* Nav item hover color - underline */
.header-nav-item--active a {
    color: #FF7F8E;
}

.header-nav-item--active a {
   background-image: #FF7F8E;
}

I have resolved.

/* Nav item color */
.header-nav-item a {
    color: #414241 !important;