“Model not supported” in Octoplus

Connect the phone to the PC and ensure the LG Diagnostics port is visible in Windows Device Manager.

The IMEI is stored in a protected, dedicated partition of your device's internal storage known as the or NVDATA/NVRAM layer. In the LG G8 ThinQ (which runs on the Qualcomm Snapdragon 855 chipset), this data is highly secured but still vulnerable to corruption under specific scenarios: