Well there's a thing. Just restarted my Win11 laptop to install the latest update and nearly all of the icons on my task bar have disappeared. The update was obviously thoroughly tested before release...
Have you run LiveUpdate manually a few times, restarting as necessary, until no updates are available? Then restart again. Restarting, not shutdown and startup again if you have Windows Fast Startup feature enabled. If you use Windows 8/8.1 or 10 or 11, there can be an issue with the Windows Fast Startup feature.. See more information here.
After a Norton update, there can be more updates waiting.