So, i have an old redmi note 5. i have unlocked its BL and install an custom rom in past. But then i thought to move to MIUI again. So i flashed MIUI 9 by mistake. Flashing Miui locked my BL and now i am stuck with miui 9(Android 7). And i am not able to update it to unlock my BL again. Is there any way to update it.

Note:
I’ve tried Unlocking its BL, Bit it shows Connect to network and try again(With Sim Card).
Downloaded An official rom zip And tried updating it via “Choose Update Package”. It throws An error cant verify.
Also i have another Redmi note 5 with latest update. But i cant download official nrom from that phone

Please help me regarding this.