Hello Ng,
Thanks for describing your situation. I’m Adrian, an Independent Advisor. I’ll walk you through what we can do. I’m here to help troubleshoot it with you.
Step 1: Disable Overlay Scrollbars in Your Browser
Overlay scrollbars can cause layout glitches like horizontal scrolling in fullscreen.
In Chrome / Edge / Brave:
Open your browser.
Chrome
Type this into the address bar and press Enter:
chrome://flags/#overlay-scrollbars
For Edge: edge://flags/#overlay-scrollbars
Set “Overlay Scrollbars” to Disabled.
Click Relaunch to restart your browser.
Step 2: Clear YouTube’s Layout Cache
While on YouTube, press Ctrl + Shift + R to force reload and reset layout cache.
Alternatively, clear site-specific cookies and data:
Go to: chrome://settings/siteData
Search for "YouTube"
Click the trash icon to delete data
Step 3: Test Without Extensions
Some extensions (like ad blockers, themes, or layout modifiers) can interfere.
Open YouTube in Incognito Mode
See if the issue persists in fullscreen
If it goes away, disable extensions one by one to identify the culprit
Step 4: Zoom & Display Settings
Make sure the browser is at 100% zoom (Ctrl + 0)
If using a high-DPI monitor or scaling, try adjusting Windows display scaling:
Go to Settings > System > Display
Set Scale to 100% or 125% for testing
Hope that helps. Please let me know if the issue still the same.
Kind regards,
Adrian A.