Android Dual-SIM issues
Not all devices implement fully and correctly the Android telephony interface. If the device does not provide dual sim signal strengths to the API17+ Android telephony interface, then the dual sim functionality of our app can not work. This is not our limitation, but it is a device/firmware issue.
Non-MediaTek devices with Android < 5.0 do not support our dual SIM app functionality. It is an Android/device issue.
In Release 3.12.0 we deployed a largely updated dual SIM engine.
If the dual SIM functionality does not work in your phone, please email us the system info/feedback from the app settings