There's a bug which doesn't happen 100% of the times but maybe 80% of the times I use DevTools.

When DevTools is open and I'm debugging or working on a website, any click on the website (left click, of course) acts like a browser's back button click. Whenever I click something, either a link or an empty space on the page, it goes back, back, back until I get back to the Speed Dial.

I don't know if this has anything to do with DevTools or not. But I'm also using mouse gestures too so this may give you an idea.

Version:81.0.4196.54 (x86_64)
System:macOS Version 10.15.7 (Build 19H2) 10.15.7 x86_64