MTK Engineer App is an App shortcut Link to access MTK Engineer and Lock 4G only. This app will work Depending your ROM device. if your device does not support this app, it will show error message. please do not rate 1 start. LTE Switcher : Shortcut to Lock LTE Only from Hidden network mode Setting 1. Select LTE Switcher - LTE Switcher 1/LTE Switcher 2/ Android One 3.0 Android 11 - Select LTE Only or 5G NR Only at Set Preferred Network type Instruction has been added to menu at Top Right Sid