Until i accessed a few settings on this page (https://restoreprivacy.com/firefox-privacy/)
specifically from Firefox About:Config settings, down.....all was well....the duckduckgo page would fill to the sides and top and bottom of the screen (without hiding the panel
I have tried reversing the changes I made with no effect.
I also tried erasing the entire about:config file....no effect
I made a new profile in Firefox, used the same addons....started it in safe mode to disable all add ons....no effect.
I completely removed one add on (Decentraleyes) because I had only added it after reading the before mentioned page.
I only changed one (1) setting in Firefox, and that was to enable https-mode in all windows.
What am I missing ????....this driving me nutty (nuttier)
I also used Timeshift to go back to the 18th May 2021.......no change.
EDIT TO ADD
By Firefox page , I mean opening a search page with my keyboard shortcut (which I have used for years), or by clicking on a link in an email (usually from Linux.org)......or if I click on the Firefox link in the panel which opens four home pages......
IF a page is already open, and I then click on a link or hit the keyboard shortcut, the opening page will be the same size as the already opened page/s
I am running Linux Mint (Cinnamon) 20.1....updated daily.