Please add this extra CSS code in Customizer -> General Settings -> Additional CSS ?:

@media screen and (min-width: 1024px){
.header-top-bar {
position:fixed !important;
min-width: 100% !important;
}

.navigation-bar {
margin-top: 60px !important
}

.fixto-fixed {
top: 0px !important;
}

.navigation-bar.coloured-nav.bordered.fixto-fixed {
margin-top: 55px!important;
z-index: 1000!important;
}
}