Default panel randomly missing on boot

Hi,
on my kde plasma manjaro I am getting a strange bug for ca a month. Sometimes when I log in to my system, the default bottom panel just won’t show up. This happens on both plasma 5.20 and 5.21. I already tried deleting ~/.config/plasma-org.kde.plasma.desktop-appletsrc, which resetted my settings but did not solve the problem.
Any ideas?

I realized that killing and restarting the plasmashell does not help, not even logging out and in again