SC1930 said

I've tried to correct this though Options and Customize but there seems to be no solution there.

Hello SC1930,

Apologies if this is a rethorical question, but did you check "Title Bar" (bottom left) and then click on the blue "Save" button ?

Firefox autohides the toolbars (Navigation Toolbar and Tab Bar) in Full Screen mode. When you hover the mouse to the top of the page then they will reappear. If you want to have them visible all the time then right-click empty space on a toolbar ot Tab bar and remove the checkmark on "Hide Toolbars".

Am I wrong assuming that with "full screen" you mean "maximize" when you say :

"Firefox keeps hiding the full screen, minimize, and close buttons. " ?

Checking "Title Bar" (bottom left) worked. There was no blue save button but the buttons are staying visible. Thank you!

I didn't enter full screen mode (would occasionally maximize), and hovering over the buttons would not make them appear.

Hello,

I am glad to hear that your problem has been resolved. If you haven't already, please select the answer that solves the problem. This will help other users with similar problems find the solution more easily.

Thank you for contacting Mozilla Support.

SC1930 said

Checking "Title Bar" (bottom left) worked. There was no blue save button but the buttons are staying visible. Thank you!

I'm glad you've got those buttons back - well done !

No wonder you didn't see a blue "Save" button - I should have said : "Done" button ........ (my apologies !).