Hello,
I think the built-in software update tool has a problem with updates – it hangs.
Then I installed Discover and was able to perform the update there.
I just wanted to put this out there for the developers to be aware of.
I’m aware that I should probably provide more information so you can better understand the issue – but unfortunately, I don’t have anything else at the moment.
That does unfortunately happen under certain circumstances. This is why I generally advise people to update from a tty by way of pacman, and if necessary, pamac as well if you have AUR packages.
An alternative — especially if you’re on Plasma — would be octopi, which is a graphical package manager that works with pacman and with an AUR helper such as yay for the AUR stuff. 
Don’t do that. discover is good for installing themes in your local account, but when using it for updating your system, it completely opens up your permissions. This is because it uses packagekit instead of polkit.
Discover is a KDE only tools to update packages. As Arch/Manjaro are different Discover should never be used on any of these distributions.
Ok Danke
I’m happy that you (apparently) got the update done - but I would suggest you promptly purge Discover - a tool not compatible with Arch or Manjaro.
Discover is a ‘KDE’ tool, but KDE Plasma is developed for and on Debian/Ubuntu systems. If you want to keep it, then disable it for updating.
When facing any issues, it’s good to simply open a terminal.
You can do several jobs there:
pacman mirrorssudo pacman-mirrors --continent && pacman-mirrorssudo pacman -Syupamac updateflatpak update.Generally, after setting mirrors and pacman sync, the GUI could well be good to go… but remember, the terminal is always your sharpest knife.