ghost/blank taskbar icons keep returning

You're experiencing persistent "ghost" or blank icons on the taskbar for some specific apps like Teams, MS Store, and ChatGPT, while others like Word and Outlook are unaffected. Given your troubleshooting steps—clean reinstall, icon cache rebuild, explorer restarts, shell re-registration, new profile, and repair install—this appears to be a more intricate issue, possibly related to system bugs, app-specific problems, or corrupt app data.