Hello, my name is Alex! Please try following the steps in the article linked below. If it doesn't help, please come back here and let me know.

Article: https://support.mozilla.org/en-US/kb/bookmarks-toolbar-display-favorite-websites#w_show-or-hide-the-bookmarks-toolbar

Sincerely, Alex

  - moz://a Volunteer

As an additional suggestion, if you store your bookmarks in all 3 places -- Bookmarks Toolbar, Bookmarks Menu, Other Bookmarks -- you could consider using the sidebar (Command+B to open/close). Keeping that open in all your windows works best with a wide display.