Kaspersky Who Calls for iOS

After the app is installed and updated, the device takes up a lot of time to update the "Call blocking and identification" settings

Due to some iOS operation issues, the settings update may take several minutes or – in rare cases – even hours.

Solution: if the Who Calls switch is not displayed in the device settings or if the switch goes back to OFF when turned on, give the app some time and come back later. If nothing changes, try restarting the device.