Thanks for reporting this bug in Ubuntu. Unfortunately there is not enough information to troubleshoot this issue.
Please attach your /etc/X11/xorg.conf and /var/log/Xorg.0.log files, and the output from lspci -vvnn. If it is possible to take a photo of your monitor while it's displaying the issue, that could be valuable as well.
Thanks for reporting this bug in Ubuntu. Unfortunately there is not enough information to troubleshoot this issue.
Please attach your /etc/X11/xorg.conf and /var/log/Xorg.0.log files, and the output from lspci -vvnn. If it is possible to take a photo of your monitor while it's displaying the issue, that could be valuable as well.