Depending on your Host, the Virtual Box version and the VM settings (especially what Graphics Controller you set for it) the VM Manjaro install and update will provide the latest virtual-guest-utils so, you should first make sure you have the latest installed on your Host too.
This will give some ideas of better practices for updating in general
In other words:
refresh mirrors sudo pacman-mirrors -f5
update the system by using sudo pacman -Syyu
you can do all at once with both commands sudo pacman-mirrors -f5 && sudo pacman -Syyu