Missed Incoming Calls on Android 4.2+ while on Wi-Fi

Starting in version 4.2 of Android, we are no longer able to override the system setting to "Keep Wi-Fi on during sleep" from within the app. 

If you are missing calls while on Wi-Fi, open the Android system settings and go to Wi-Fi, then hit the menu button (3 dots on bottom right) and select "Advanced".  From there, ensure that "Keep Wi-Fi on during sleep" is set to "Always".