Okay about a month ago my private browsing would turn on when I opened Firefox. So I would turn it back off, and then do whatever I came to do. But then when I would close the browser and open it again, private browsing would turn on again. I'd done everything, and finally, a couple weeks later, I got it to stop. So it'd been about 2 weeks and it wasn't turning back on, but just today it did it again!! What is going on?
Start Firefox in Safe Mode to check if one of the extensions (Firefox/Tools > Add-ons > Extensions) or if hardware acceleration is causing the problem (switch to the DEFAULT theme: Firefox/Tools > Add-ons > Appearance).
Do NOT click the Reset button on the Safe mode start window or otherwise make changes.