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 Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/1849711 Title: Only GRUB2 have MAX BRIGHTNESS in 19.04 and 19.10 Status in linux package in Ubuntu: Incomplete Bug description: whenever I boot into Ubuntu the grub 2 boot loader have maximum brightness but after selecting Ubuntu OS, system return to its normal brightness value , previously my Ubuntu version is 19.04 and this problem exists but after upgrading to 19.10 this issue still there and nothing works by upgrading system, grub remains at high brightness value (even function keys not working at that time). Every time i reboot the system the grub 2 have max brightness and it returns to normal brightness after reaching to log on screen and then everything works fine even functions keys also working. laptop specs: AMD reyzen 3 2200u AMD Radeon Vega 3 HP g7 245 ProblemType: Bug DistroRelease: Ubuntu 19.10 Package: xorg 1:7.7+19ubuntu12 ProcVersionSignature: Ubuntu 5.0.0-32.34-generic 5.0.21 Uname: Linux 5.0.0-32-generic x86_64 ApportVersion: 2.20.11-0ubuntu8 Architecture: amd64 BootLog: Error: [Errno 13] Permission denied: '/var/log/boot.log' CompositorRunning: None CurrentDesktop: ubuntu:GNOME Date: Thu Oct 24 21:52:44 2019 DistUpgraded: Fresh install DistroCodename: eoan DistroVariant: ubuntu ExtraDebuggingInterest: Yes, if not too technical GraphicsCard: Advanced Micro Devices, Inc. [AMD/ATI] Raven Ridge [Radeon Vega Series / Radeon Vega Mobile Series] [1002:15dd] (rev c5) (prog-if 00 [VGA controller]) Subsystem: Hewlett-Packard Company Raven Ridge [Radeon Vega Series / Radeon Vega Mobile Series] [103c:8562] MachineType: Hewlett-Packard HP 245 G7 Notebook PC ProcEnviron: LANGUAGE=en_IN:en PATH=(custom, no user) XDG_RUNTIME_DIR=<set> LANG=en_IN SHELL=/bin/bash ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-5.0.0-32-generic root=UUID=380079ae-40a6-4aed-8280-2b263a41cf1e ro quiet splash acpi_backlight=vendor quiet splash vt.handoff=7 SourcePackage: xorg Symptom: display UpgradeStatus: No upgrade log present (probably fresh install) dmi.bios.date: 07/03/2019 dmi.bios.vendor: AMI dmi.bios.version: F.42 dmi.board.asset.tag: Base Board Asset Tag dmi.board.name: 8562 dmi.board.vendor: Hewlett-Packard dmi.board.version: 84.24 dmi.chassis.asset.tag: 5CG9212QLP dmi.chassis.type: 10 dmi.chassis.vendor: Hewlett-Packard dmi.chassis.version: Chassis Version dmi.modalias: dmi:bvnAMI:bvrF.42:bd07/03/2019:svnHewlett-Packard:pnHP245G7NotebookPC:pvr:rvnHewlett-Packard:rn8562:rvr84.24:cvnHewlett-Packard:ct10:cvrChassisVersion: dmi.product.family: 103C_5336AN HP 200 dmi.product.name: HP 245 G7 Notebook PC dmi.product.sku: 6JM93PA#ACJ dmi.sys.vendor: Hewlett-Packard version.compiz: compiz N/A version.libdrm2: libdrm2 2.4.99-1ubuntu1 version.libgl1-mesa-dri: libgl1-mesa-dri 19.2.1-1ubuntu1 version.libgl1-mesa-glx: libgl1-mesa-glx N/A version.xserver-xorg-core: xserver-xorg-core 2:1.20.5+git20191008-0ubuntu1 version.xserver-xorg-input-evdev: xserver-xorg-input-evdev N/A version.xserver-xorg-video-ati: xserver-xorg-video-ati 1:19.0.1-1ubuntu1 version.xserver-xorg-video-intel: xserver-xorg-video-intel 2:2.99.917+git20190815-1 version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau 1:1.0.16-1 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1849711/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp