How to fix WordPress Toolbar submenu links issue with sticky header

In Oxygen when the header becomes fixed on the front end, the links in WordPress Toolbar submenus can’t be reached as they will be covered by the fixed header.

Adding the following CSS will fix this issue:

/* Make the admin bar menu items visible on top to accomodate the fixed header */
@media (min-width: 993px) {
#wpadminbar {
z-index: 2147483640;
}
}