I have a Redmi 12C with conflicting variants: sideload mode shows…

I have a Redmi 12C with conflicting variants: sideload mode shows China, while Settings and the back cover indicate Global. The baseband is Unknown. I've tried dual-IMEI repair without success. Both IMEIs appear on the engineering ROM but disappear on stock ROM. Any suggestions or compatible firmware files to fix the baseband and restore IMEI visibility? Nb : global rom doesnt boot on this device