As others have noted...
I am able to reproduce always, with gpupdate /force with the following caveats:
- The same instance of Explorer window will only steal foreground/focus once, and not again, during subsequent gpupdate /force's
- If the Explorer window is ever minimized previously, it does not seem to steal foreground/focus during gpupdate /force
@Diplocaulus, try:
- Completely closing "File Explorer"
- Open "File Explorer"
- *Background "*File Explorer," but do not minimize, by selecting any other window (including your command window)
- Run the command "gpupdate /force"
You may also notice your desktop icons refreshing when this happens as well.