Mio BKM4g Cadance and RPmm sensor

I using a Mio BKM4G sensor it work with My mio 505 and it connects using other apps on my samsung s5 but the Zwift app will not connect to it.

Is it Bluetooth or Ant+? If it is Bluetooth make sure you have disconnected it from all other apps and devices including the phone. I am guessing you are talking about the Zwift Mobile Link and that is for bridging Bluetooth, not Ant+. If you are using Bluetooth make sure in Settings>Sensors that you have BLE turned on. 

Its Ant+ On the android app. Using other apps (Wahooo app in this  case) can see the sensor fine. So don’t think its BLE mode that the problem, but ill check.