I have a Samsung Galaxy Note 22 Ultra. Originally T-Mobile, but it was unlocked and is now on US Mobile Lite speed (using T-Mobile network). This problem is carrier-independent.
I live on a hill, and there is very limited cell signal indoor. The phone often switches between 4G and 5G all on its own even when set stationary on my desk in my home office. If I move around the house, it will sometimes hit cell dead spots, too. Even when the phone has cell signal, data transfer speed (speedtest) is measured in kbps, not mbps. Incoming calls seldom get through when the phone is on cell signal. Texting usually does, but sometimes with a lag of several minutes. Outgoing texts often get stuck and need to be resent. Basically, the cell signal is useless. I have tried other carriers, and they are even worse. Between the terrain on the hills, and the very strong building materials in my mansion, it is akin to a Faraday cage. I tried installing cell booster/repeater before, but it did not help, because the signal outside is too weak, especially during inclement weather. The booster actually made things worse.
Because of this, I have a 6-AP Unifi mesh Wifi system. I set Wifi calling preferences to "Wifi preferred". Obviously, I don't want cell to ever be the priority. Unfortunately, periodically, the phone shows the message "Wifi calling preferences have been optimized". And it resets the preference to "Cellular preferred". This happens every single day. How can I make the setting stick ?
The only workaround I can think of is to disable mobile data when I am at home, or put the phone in airplane mode, but that is not a great solution, as I may forget to turn it back on when I leave the house.
I found another thread about another user having the same issue on an S21 ultra. He solved it by disabling "switch to mobile data" under intelligent Wifi. Unfortunately, that setting was already off on mine. I just disabled all the other options under intelligent Wifi as well, but I doubt that will have the desired effect of locking the Wifi calling preferences.
I just did that. Used airplane mode and turned off Wifi calling. Called my cell phone from Google voice over Wifi. The call rang on my VoIP line, which uses voip.ms with a Grandstream HT802. Pretty neat ! I left a voice mail, and it ended up in my Google mailbox as an MP3 . Voice quality was awful in that MP3, though. Not sure if the call forwarding has something to do with it.
I also sent an SMS from Google voice to my cell. The SMS did not get forwarded to my VoIP line. That line does support SMS, and I normally get the texts sent to it in my Gmail, also. Once I turned off airplane mode, my smartphone received that text. Looks like the "text forwarding" feature is missing. It's not as big of a deal, though, as the texts should eventually get there with Wifi calling, even with a weak Wifi signal.
Wifi calling can work in the air under some circumstances. I'd love to describe what those are, but this forum keeps telling me I'm using a blocked word, without telling me which one it is, and I'm not going to make 100 edits to figure out what it is.
I remember when that started working. I find it odd that cellular features work even on WiFi when airplane mode is on. If I'm not mistaken, that wasn't always the case, but I could be remembering wrong. I remember the time that I noticed it working that way for the first time.
The routine is unfortunately not good enough. A problem occurs when the ISP goes down, which it did earlier this weekend during a storm. My phone remains connected to the Wifi access point in this case. That is intentional. It is so that I can continue to use the Home Assistant home automation system on my LAN, which continues to work even if Internet goes down. So, the phone is connected to the Wifi without Internet.
In this case, the call forwarding to the VoIP line does not work, since the ISP is down. Only a fallback to cellular could work. It doesn't, because the phone is in airplane mode, and mobile data is disabled. That means no calls are possible, inbound or outbound.
I tried to turn off Wifi manually when this occurred. But the phone immediately turned Wifi back on. Disabling the routine stopped that behavior. I do not know why the routine turns Wifi back on. The routine should only trigger when connecting to the home's SSID. It shouldn't trigger when disconnecting from it. But it does.
I don't think any routine can emulate fixing the bug in the phone's firmware to honor the Wifi calling preferences.
You can't make a Wi-Fi call if the Wi-Fi signal is not connecting to the internet, so just because it is connecting to your Wi-Fi, if the router is down or there's a network outage in your area, you will still not be able to make Wi-Fi calls. The routine might turn Wi-Fi back on if your phone settings are set to reconnect to your network automatically. Wi-Fi calling only works when there is an active connection to the internet, not just a LAN. Of course it won't go to the VOIP line, because the VOIP line is not connected to the internet either.
If you are aware that your connection to the internet was lost, you will have to manually take your phone out of airplane mode so that you can use the cellular network.
I'm obviously aware that Wifi calling won't work if the Wifi is connected, but there is no Internet connection. That's why I want to turn on mobile data when this happens.
1) To accomplish this, I first tried to turn off Wifi. However, that caused the routine to end, because the phone was no longer connected to my home Wifi. At that point, the routine restored the previous state of Wifi, which was on. Then, my phone reconnected to the home Wifi. Then the routine started again, and turned on airplane mode. As a result, mobile data was turned off once again.
2) Trying to turn on mobile data manually produced the message "Can't connect to mobile networks while airplane mode is on".
3) Turning off airplane mode worked. It did not end the Wifi connection, and enabled mobile data. However, if I then subsequently turn off Wifi on the phone, it goes back into the situation described in 1) above.
I would say this is still suboptimal, even if one is still aware of this behavior, for the following reasons. It is tricky to remember the above behavior, especially during an emergency.
If I'm asleep during the home ISP outage, I won't be able to change the setting. But I especially need to be able to receive inbound cellular calls in this case. I live in both an earthquake and brush fire area, and am signed up to receive emergency calls from the county on both my home VoIP line and my cell phone line. The other day, the storm happened during the night, while I was asleep, and while the ISP was offline. There was a county emergency notification, which I missed, though no evacuation order, thankfully. Unlike in my office where cell is worse than useless, I do happen to have a strong cell signal in my bedroom upstairs, likely because the tower is higher up on the hill, so I would receive these calls while asleep if the fallback to cellular was enabled. I would probably still not wake up, though, because my phone is always on Do not Disturb at night. I just added the county notification number to the exception list for Do not disturb.
What I would like to do is for the routine to work transparently when the ISP goes down, and automatically enable mobile data, without disconnecting from the home Wifi.
I don't see a way to do that with the existing routines. I think it would be a lot simpler for Samsung to fix the bug with Wi-fi calling priorities than add the missing logic options to accomplish what I need.
Having Samsung fix it may be the optimal solution, but since WiFi calling is on the carrier, it may not be Samsung's issue to fix. There are currently no routines that detect "connected without internet", so I think *that* is where Samsung can make an improvement. Can add a routine for if internet is not detected, turn off airplane mode and disconnect from wifi. You can also, in the meantime, try having the routine ending with turning wifi off instead of returning it to the on state.
The routine actually does work when your internet works. I assume it does not go out on a daily basis. Of course a routine like this requires a stable internet connection.
