If basic software repairs fail, the IMEI must be manually rewritten to the device's secure partition.
Write IMEI manually (last resort / for authorized repairs) repair imei sony xz3
Physical drops or water damage causing intermittent failure in the motherboard's baseband IC chip. Symptoms of a Damaged IMEI If basic software repairs fail, the IMEI must
If you have tried all the methods described above (particularly the stock firmware re-flash) and your IMEI remains invalid, it may be a hardware problem. This could be a faulty eMMC memory chip, a corrupted baseband flash storage, or a problem with the motherboard. In this scenario, your best recourse is to: If basic software repairs fail