I just ran (Sept 2, 2021) into this issue in an SSD that I was using to debug Ub20.04 freezing completely. I installed 20.04 froze. Then I installed 18.04 in the same SSD to see if that will run properly since I was blaming snaps for the crash, by the way I removed snaps from this 18.04 install. My original 18.04 in another ssd started having freezing issues when Snaps was added to it.
It turned out to be the video card. Removed it and everything seems fine. When I rebooted 18.04 it did an
unattended update, don't turn off your computer.
After this I tried to boot into 20.04 and got the message
fsck error on boot: /dev/sda6: UNEXPECTED INCONSISTENCY; RUN fsck MANUALLY.
I did from the initfram error screen
fsck -fy /dev/sda1
sudo apt-get update
sudo apt-get clean
sudo apt-get update
sudo apt-get upgrade
Everything is fine now. So I blame the playing with the install, not the SSD.
journalctl /dev/sda6
will show you more information. – waltinator Jul 29 '18 at 16:57