I think Ubuntu 19.10 is better at remembering your previous brightness values and yes indeed that will change after grub2. So I don't think this is a bug. Unless you're saying it's the wrong brightness value being remembered?
See also (probably unrelated) bug 1848360 ** Package changed: xorg (Ubuntu) => linux (Ubuntu) ** Changed in: linux (Ubuntu) Status: New => Incomplete -- You received this bug notification because you are a member of Ubuntu-X, which is subscribed to xorg in Ubuntu. https://bugs.launchpad.net/bugs/1849711 Title: Only GRUB2 have MAX BRIGHTNESS in 19.04 and 19.10 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1849711/+subscriptions _______________________________________________ Mailing list: https://launchpad.net/~ubuntu-x-swat Post to : ubuntu-x-swat@lists.launchpad.net Unsubscribe : https://launchpad.net/~ubuntu-x-swat More help : https://help.launchpad.net/ListHelp