@hellomiakoda @fredds ok... well going back to a more simple approach. Do you have any old kernels still installed whose modules could be taking up needless space in the /usr/lib/modules directory? Maybe try cleaning those out? I'm assuming the contents of that directory, even as a tmpfs mount, still contains the kernel modules.
I see in another post your are running Suse, last I used that distro was about 20 years ago so i'm not sure if the /usr/lib/modules as a tmpfs mount is deliberate or some strange race condition due to your failed upgrade.