Having the same problem with LibreELEC-AMLGX.arm-11.0.1-box.img.gz
I can SSH into the box if I get it between when ssh starts and when the screen blacks out. However I only have a few seconds to do anything before it goes tits up.
It appears something is going wrong with IO, and would explain why you can't SSH in after the issue (anything not loaded into page cache is unreadable).
In any case, since IO is in a borked state, and don't have access to anything not in page cache, I'm not sure what info I can provide. However I did run dmesg before it died, so I do have access to that.