IMEI issues on Xiaomi and POCO devices typically occur after a botched custom ROM installation, improper flashing via Mi Flash Tool, or an interrupted system update that corrupts the device's EFS partition.
If the IMEI is truly gone ("Null"), you will need to write a new QCN file to the Qualcomm Snapdragon 732G chipset. Requirements: QPST Tool (Qualcomm Product Support Tool) QCN file Poco X3 NFC Go to product viewer dialog for this item. Root access (Magisk) Steps: repair imei poco x3 nfc
Erase modemst1 / modemst2 via Fastboot or write QCN file via Diag Mode. Broken modem communication or partition block IMEI issues on Xiaomi and POCO devices typically
Before proceeding, it is critical to understand the legal and technical implications: improper flashing via Mi Flash Tool