On the LG V50, IMEI data is stored in sensitive partitions like modemst1 , modemst2 , and fsg . Repairing these usually requires specialized software tools and low-level access to the device's Qualcomm Snapdragon 855 processor.
Type in the original IMEI from your device's sticker or box and click Start Procedure . Alternative: Custom ROMs and TWRP lg v50 imei repair