Configuration non-persistence issue with my SenseCAP M2 4G

Hello everyone,

I have a critical configuration non-persistence issue with my SenseCAP M2 4G MT7628 gateway. Nothing is being saved after a reboot.

Situation :
I couldn’t get my SIM card to work for data, so I asked support for help but got no response at my emails.
I tried to fix it myself by following the wiki’s instructions to flash a new firmware version. Since then, I’ve had the problem where it doesn’t keep anything in memory.

I have already attempted all OpenWrt software repair steps (factory reset, MTD erase, and reflashing the firmware without keeping settings). The issue persists.

The logs :
The operating system refuses to mount the data partition (/overlay) due to a JFFS2 version incompatibility error (“Old JFFS2 bitmask found”).

Have you encountered this issue before?
Is there a solution?

Thank you very much for your help!