LinkPi ENC1-V2 - read only flash memory

We have been using several LinkPi ENC1-V2 units for about four months.
We cannot change the configuration of more than half of the units.
After a reboot, the web interface is no longer accessible.

On the console/ssh we see that the root filesystem is read-only from boot.
It seems to be a bad block on the flash card that puts the filesystem in this mode.

Here is the dmesg extract.
UBI: dumping 2048 bytes of data from PEB 1373, offset 0
UBI error: erase_worker: failed to erase PEB 1373, error -5
UBI error: erase_worker: no reserved/available physical erase blocks
UBI warning: ubi_ro_mode: switch to read-only mode

Does anyone know of a way to fix this error via the console (SSH)?

Thanks for any advice.