My wife and I recently upgraded to S21 ultras. Right after we upgraded we noticed that we were not getting phone calls or texts when we had the wifi turned on (data still on, not in airplane mode, just turned on wifi without any other changes). If we turn off the wifi, the calls and texts come through like normal. Took the phones back to the verizon store but they couldn't figure it out either. This is very dangerous as I might be calling the wife in case of emergency and it goes straight to voicemail and she never gets a notification of a call or any of my texts until the wifi gets turned off and all the texts come through all at once.
Update: We think we found the cause. This will need to be investigated by tech support to find out why this setting is not working properly. We disabled Wi-Fi Calling and got calls to go through. When Wi-Fi Calling was turned on with WiFi on, it limited phone calls and text as the WiFi did not support Wi-Fi calling. It shouldn't restrict calls and texts to only wifi, if the data network is still available it should allow calls and texts to continue to go through regardless if Wi-Fi Calling is on and regardless if the WiFi is connected. Sometimes we're watching videos and turn the wifi to reduce the buffering. While watching the videos calls weren't going through. We would message via facebook or something, turn off the wifi and then be able to call. With the Wi-Fi Calling turned off, the calls were going through.
If this is a problem with the phone and the settings, then the Wi-Fi Calling feature should not be defaulted to be on when getting new phones.
