If you’re facing the issue in a browser, try opening other apps to see if the issue persists in them. If you’re facing the Windows 10 taskbar not hiding in fullscreen issue, chances are, it might be an issue with the app in which you’re trying to use the fullscreen mode. Use A Different Browser Or Reinstall The App
Pressing the F11 key to get out of the full screen and pressing it again to get into full-screen mode can also sometimes do the trick.
