Hello,
Having Firefox 81.0.2 under Kubuntu 18 I would like to set bigger default font size for
it and I found fonts options : https://prnt.sc/vjjotn
but setting big value as default size, but it does not applied.
On opening firefox has small fonts.
I suffered a brain fart when making my post (#3 ).
This caused me to believe that the option was
related to the font size. Obviously, I now see that
it was not.