The issue is not caused by unattended-upgrades, but by whatever installs the transitional firefox package over the PPA-installed package.
The issue in unattended-upgrades is *related*, though. ** Changed in: firefox (Ubuntu) Status: Invalid => Confirmed -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1999308 Title: Snap keeps uninstalling apt Firefox, and reinstalling snap Firefox To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/firefox/+bug/1999308/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs