I have the same problem. My configuration is :
- RPI3 A+
- 128GB msata SSD on SSD to USB adaptator
- No sdcard (USB boot)
My configuration work correctly with L10.0.4
I upgrade to L11 and after the upgrade, the system hanged up with the message : Could not mount /flash/SYSTEM
I try manual upgrade with L11 nigthly build :
- LibreELEC-RPi2.arm-11.0-nightly-20221231-b9ea43f.img.gz OK (kernel 6.1.0)
- LibreELEC-RPi2.arm-11.0-nightly-20230129-c2ff0c7.img.gz OK (kernel 6.1.8)
- LibreELEC-RPi2.arm-11.0-nightly-20230228-80ac358.img.gz KO
So the problem appears between 20230129 and 20230228. I will try with february builds to find which build make the problem.