Nothing apparent using Firefox 91.0.1 on Linux Mint.

John

Hi, I've not seen any, W10 – MS Edge.

Regards Nick.

Just for the sake of curiosity … Could you take a photograph of your screen, so that we know what we’re missing.

MichaelG.

Thanks, Anthony

… No, I’ve never seen that

MichaelG.

You can try running a colour screen test program to see if there is any problem with your pixels.

I'm using Firefox on Ubuntu 18.04, and 21.04 without white spots.

Before reinstalling the whole of Ubuntu I'd remove and reinstall Firefox: could be Firefox is corrupt.

Hold down Ctrl, Alt and hit 'T' to get a terminal.

In the terminal, at the $ prompt, type:

sudo apt-get remove firefox

Hit return, enter password, and a stream of removal messages should be displayed. When finished, type:

sudo apt-get update

This makes sure your computer is synchronised with Ubuntu's internet software repositories. Then, type:

sudo apt-get install firefox

Although rebooting isn't necessary, it does clear everything out, so worth doing whenever corruption is suspected. Cross fingers. restart the system. then and test the Green Banners.

Postscript: there is a more nuclear version of the remove command. remove doesn't delete user configuration settings, cookies etc. If you don't care about them, replace:

sudo apt-get remove firefox

with

sudo apt-get purge firefox

Good luck

Dave

My go to reference is:

"Linux Command Line and Shell Scripting Bible", by Blum.

Russell