BluetoothThis code doesn't work on at&t.
I have found a tweak that has worked for me.
I live in NYC and have TMobile. Switched from a Motorola g4+. Immediately after switching to the Zenfone 6 I started to have issues making calls and getting them (didn't happen with the g4+). The signal bar would show a good signal, but calls would not go through. More than once I missed an important call because the person calling me got sent directly to voicemai, even though I had my phone next to me in my bedroom in a 3rd floor next to a window.
I kind of figured that it might have to do with the LTE. So I went to the phone settings where you can force the phone to only use 3g. But it turns out that it doesn't work.
Long story short, this is the solution I found. There is a way to access the phone's advanced cellular settings. Where you can choose to keep the phone from using 4g LTE:
1. Punch this into the dial pad #*#4636#*#
This will take you to this screen:
2. Select Phone Information.
It'll take you to this:
I can't show the top of the page because it has my phone's info, and I was too lazy to edit it out. Here you see the bottom part of it.
3. Change the Set Preferred Network Type to Global Auto (PRL). Give it a couple of seconds and you'll see the information above this setting change from LTE to in my case HSPA and UMTS.
With this setting modified, I now have the same connectivity as I did with my G4+. Haven't noticed a big change in the data speed. I can still stream 480p YouTube videos when I have a solid signal. And the calls are decent in quality. Nothing like the HD audio you get with VoLTE, but it's better than nothing.
I first tried 3G only, but I couldn't even load Google some times. Calls were ok though.
Absolutely love all other aspects of my Zenfone 6, but if I had been aware of this issue before purchasing the phone, I would have spent my money on something else.