Happened first after upgrading from 19.10 to 20.04 used it for a while until that happened. I then tried by formatting and made a clean install on an encrypted ext4 filesystem, installed some applications, used it for like an hour and it got back to the same spot. Wouldn't let me save any file, and when trying to suspend or reboot it displays a cascade of warnings about the read-only file system issue.
Besides upgrading to 20.04 the only difference with the software I was using on 19.10 is the Canonical Livepatch service.
I'll be formatting and switching back to 19.10 at least until 20.10 is available.
No support needed, just an input for developers.