Sound that something in that window is trying to get focus.

What kind of content is in the window that gets focus ?

Are you opening all links in a new window or is this only about pop-up windows that Firefox opens by itself ?

Start Firefox in Safe Mode to check if one of the extensions ("3-bar" menu button or Tools -> Add-ons -> Extensions) or if hardware acceleration is causing the problem.

• switch to the DEFAULT theme: "3-bar" menu button or Tools -> Add-ons -> Themes
• do NOT click the "Refresh Firefox" button on the Safe Mode start window

• https://support.mozilla.org/en-US/kb/troubleshoot-firefox-issues-using-safe-mode
• https://support.mozilla.org/en-US/kb/troubleshoot-extensions-themes-to-fix-problems

Hi Cor-el,

Thank you for the reply, I didn't get notified so it's taken me this long to decide to look for a solution again and come across my post....

It happens between all windows, firefox, chrome, and even spotify and discord. All my researching for answers pointed towards Firefox and hence I posted here. Doesn't seem connected to links, as it happens constantly even when I haven't clicked anything or touched my keyboard in minutes.

I will use safe mode and let you know if the issue persists. It very well may not be firefox, just everywhere I look points to it.

Thanks again. I'll get back to you.

Hi Cor-el,

It still happened with firefox entirely shutdown, and using chrome. So it wasn't firefox. I realised that my dual monitor program "Display Fusion" may also have something to do with it, as it felt like something it'd have some control over. It turns out it is in fact the source of the problem, a setting on it (an independent task bar on the separate screen) which paired with a recent windows update causes the random switching.

Thanks again for your time, and I apologise to Firefox for accusing it of being the problem lol.