When there's a Fwupd update and you install it, it just immediately disappears once it's finished, but it will re-appear if you check for updates again. In fact the update has simply been queued for the next reboot and it will complete normally. But this the UX has some problems:

1. Because the available update disappears immediately when you install and then re-appears when you check for updates again, you can be left with the incorrect impression that the update failed.
2. There is no notification that the update has been queued for the next reboot.