Is the title bar currently visible ?

• you can toggle the title bar on/off via the "Title Bar" button at the bottom left in the Customize palette window

Are you possibly using code in userChrome.css to move the tab bar to the position below the Navigation Toolbar ?

• https://www.userchrome.org/what-is-userchrome-css.html

My title bar was off.

I have not touched userChrome.css. Can an inadvertent key click change it?

By navigation bar do you mean the bar with the <- and ->, reload icon and URL address bar?

Your screenshot shows the standard layout with the title bar hidden and with the menu bar visible. If you previously had the tab bar in a different (lower) position then this can only be achieved via userChrome.css.

You didn't confirm whether you are using a userChrome.css file in the chrome folder in the profile folder. If you do use it then it looks that the file is broken or that you do not have it enabled.

In Firefox 69 and later you need to set this pref to true on the about:config page to enable userChrome.css and userContent.css in the chrome folder.

• toolkit.legacyUserProfileCustomizations.stylesheets = true
• https://www.userchrome.org/firefox-changes-userchrome-css.html