Screen flickering in Windows 11 is usually caused by a display driver issue or incompatible app. To determine whether a display driver or app is causing the problem, check to see if Task Manager flickers. Then, based on that information, you'll need to update, rollback, or uninstall your display driver or update or uninstall the app. More @Wikipedia
Hover over any link to get a description of the article. Please note that search keywords are sometimes hidden within the full article and don't appear in the description or title.