FF is smaller than the screen ubuntu
I have to change the resolution ( xrandr --output HDMI-1 --mode 1920x1080) but FF does not resize, please could you look at the image that I have attached?
Thanks in advance!
As a user of Ubuntu myself, I believe this is the desktop environment saving the previous size of Firefox.
Try resizing Firefox and restarting it afterwards, it most likely will startup with the new size.