Yup, the issue is gone in FVD 68.7.5! Thanks!

No prob

Just emailed you the link 👌

May I know your email or is it possible to DM you the link here?

I've done the recording but how I can share it to you securely? If you've got a GPG key pair I can simply encrypt the file and upload it here?

Hmm... ok but I'm gonna need a little while to get prepared for this...

Are you gonna try tweaking some of my configurations to see whether you could fix it or you simply want to know how exactly the issue is and the way to reproduce? If it's the latter one I can actually do a screen recording for you.

I'm using the same Firefox account on a Mac and everything is synced but I cannot reproduce the same issue on the Mac.

So I tried Help | Troubleshooting Information | Refresh Firefox Developer Edition to reset all settings of Firefox in Linux and the same problem just happened again... However if I create a new profile and install only FVD it's then all good.

I guess it's somehow an about:config setting that's persistent across 'refreshes' but I've got tons modified settings and completely no idea which one it might be.

It is turned on and everything works normally if I disable FVD. And I noticed that if I click on other tabs immediately after Firefox is started, those tabs are either redirected to new tab page or to some websites in my browsing history.

PS: just upgraded to FVD 68.7.3, same issue.

This also causes incorrect behaviour if one tries to open a link when Firefox is closed.