i did some experiments with software-raid on my xubuntu 20.04. I created a raid with 2 hard drives and mounted it using the fstab. after that i couldn't shut down the system with the shutdown button of the xfce start menu. i've disabled that raid and created a new one with 2 ssd. Here all works fine and i could shutdown the system. back to the hard drives, new raid and again the problem: i can't shut down the system using the xfce shutdown button. I works with
sudo shutdown now
in terminal. what is the problem?