Screen bug

[Treve Winchcombe]

I have this weird screen bug that was not present on Windows, the OS I used before Ubuntu. I have reinstalled Ubuntu but this has not fixed the issue. When scrolling or watching a video in full screen, there are two bars that appear in the middle of the screen widthways.

The bars are transparent but you can still see the outline of them and they also move around slightly meaning it can be quite distracting. The bars are not there when doing other tasks like general work like web browsing and email unless you scroll.

It seems to only be an issue when a large part of the screen has to refresh at any one time.

ProblemType: Bug
DistroRelease: Ubuntu 20.04
Package: xorg 1:7.7+19ubuntu14
ProcVersionSignature: Ubuntu 5.4.0-42.46-generic 5.4.44
Uname: Linux 5.4.0-42-generic x86_64
.tmp.unity_support_test.0:

ApportVersion: 2.20.11-0ubuntu27.4
Architecture: amd64
BootLog: Error: [Errno 13] Permission denied: '/var/log/boot.log'
CasperMD5CheckResult: skip
CompositorRunning: None
CurrentDesktop: ubuntu:GNOME
Date: Mon Jul 27 16:22:20 2020
DistUpgraded: Fresh install
DistroCodename: focal
DistroVariant: ubuntu
DkmsStatus: virtualbox, 6.1.10, 5.4.0-42-generic, x86_64: installed
ExtraDebuggingInterest: Yes, if not too technical
GraphicsCard:
 Intel Corporation Iris Plus Graphics G7 [8086:8a52] (rev 07) (prog-if 00 [VGA controller])
   Subsystem: Lenovo Iris Plus Graphics G7 [17aa:3f1a]
InstallationDate: Installed on 2020-07-22 (4 days ago)
InstallationMedia: Ubuntu 20.04 LTS "Focal Fossa" - Release amd64 (20200423)
Lsusb:
 Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
 Bus 001 Device 002: ID 13d3:56b2 IMC Networks Integrated Camera
 Bus 001 Device 003: ID 8087:0aaa Intel Corp.
 Bus 001 Device 004: ID 1ea7:0066 SHARKOON Technologies GmbH [Mediatrack Edge Mini Keyboard]
 Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
MachineType: LENOVO 81VV
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-5.4.0-42-generic root=UUID=1664842e-9af5-44b6-a3c8-f9235f094044 ro quiet splash vt.handoff=7
SourcePackage: xorg
Symptom: display
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 05/27/2020
dmi.bios.vendor: LENOVO
dmi.bios.version: CUCN21WW(V1.10)
dmi.board.asset.tag: NO Asset Tag
dmi.board.name: LNVNB161216
dmi.board.vendor: LENOVO
dmi.board.version: SDK0R32776 WIN
dmi.chassis.asset.tag: NO Asset Tag
dmi.chassis.type: 10
dmi.chassis.vendor: LENOVO
dmi.chassis.version: Lenovo IdeaPad S340-14IIL
dmi.modalias: dmi:bvnLENOVO:bvrCUCN21WW(V1.10):bd05/27/2020:svnLENOVO:pn81VV:pvrLenovoIdeaPadS340-14IIL:rvnLENOVO:rnLNVNB161216:rvrSDK0R32776WIN:cvnLENOVO:ct10:cvrLenovoIdeaPadS340-14IIL:
dmi.product.family: IdeaPad S340-14IIL
dmi.product.name: 81VV
dmi.product.sku: LENOVO_MT_81VV_BU_idea_FM_IdeaPad S340-14IIL
dmi.product.version: Lenovo IdeaPad S340-14IIL
dmi.sys.vendor: LENOVO
version.compiz: compiz 1:0.9.14.1+20.04.20200211-0ubuntu1
version.libdrm2: libdrm2 2.4.101-2
version.libgl1-mesa-dri: libgl1-mesa-dri 20.0.8-0ubuntu1~20.04.1
version.libgl1-mesa-glx: libgl1-mesa-glx N/A
version.xserver-xorg-core: xserver-xorg-core 2:1.20.8-2ubuntu2.2
version.xserver-xorg-input-evdev: xserver-xorg-input-evdev N/A
version.xserver-xorg-video-ati: xserver-xorg-video-ati 1:19.1.0-1
version.xserver-xorg-video-intel: xserver-xorg-video-intel 2:2.99.917+git20200226-1
version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau 1:1.0.16-1

[Daniel van Vugt (vanvugt)]

Unfortunately you appear to be using two features that will cause this:

Fullscreen windows on the modeset Xorg driver: bug 1754284

Fractional scaling on the modeset Xorg driver: bug 1846398

The only ways to avoid the bars (screen tearing) on a system like yours would be:

 * Choose 'Ubuntu on Wayland' from the login screen to avoid Xorg; or

 * Avoid fullscreen windows and avoid fractional scaling, when using Xorg.