Your YouTube flickering issue is commonly caused by conflicts between your browser's hardware acceleration and your graphics card, outdated or incompatible graphics drivers, incorrect display settings, or interfering browser extensions. To fix the flickering, you can try these steps:

1. Disable hardware acceleration in your browser settings. This option is usually under Settings > System > Use hardware acceleration when available. Toggling this off often resolves flickering because it stops your browser from utilizing the graphics card in a conflicting way.
2. Update or reinstall your graphics drivers. Outdated or buggy drivers can cause flickering during video playback. Use your graphics card manufacturer’s software (like NVIDIA GeForce Experience or AMD Radeon Software) to get the latest stable version.
3. Check your Windows display settings such as refresh rate, resolution, and scaling to ensure they are at recommended values. Incorrect settings can lead to flickering especially with high-resolution videos.
4. Disable browser extensions one by one to identify if any are causing the problem, since some extensions interfere with video playback.
5. Clear your browser cache and cookies, as corrupted data might contribute to flickering.
6. Try watching YouTube videos in a different browser to determine if the issue is browser-specific.

Applying these solutions typically fixes YouTube flickering for most users.