In order to not miss any calls, the Hushed app needs to be running in the background at all times. If the app is shut down, you will not be able to receive any calls or texts until you open the app up again, where you will then see the missed call and SMS logs.
If "Background Refresh" is off, then the app cannot receive messages while it is in the background and might not be able to perform calls. To resolve this, please follow these steps:
For iOS Devices
To enable this, there are 2 options to check :
1 - Low Power Mode (Settings App - > Battery - > Low Power Mode) needs to be off
2 - Background App Refresh (Settings App -> Hushed - > Background App Refresh needs to be ON
If Background refresh is greyed out in the ON position, go To Settings App - > General - > Background App Refresh - > Turn on the option for the system, and then you can turn on / off by app.
For Android Devices
Would you be able to do the following:
In your device, go to Settings menu > Battery > top right 3 dot icon > Battery optimization > click on "Not Optimized" bar > All Apps > Hushed > Select "Don't Optimize".