Unreliable cellular connection on a new phone :(

[FAHMI BASSEM]

Hello!
Here's a detailed description of my issue:
1. 4G works, text works, but not phone calls (receiving neither calling); if someone calls I'm offline for him
2. After any attempt to call, the connection is either lost -offline- or connected but with lost data download/upload for a minute
3. Phone calls worked only for once (received)

Tried switching sim to 2nd tray (dual sim device) with no success; I also tried resetting configuration files with same result

What could be the problem? What do you suggest?

Thank you in advanced...

 

[Rukbat]

The problem could be the carrier. Bring the phone into them (suggested) or call their tech support number (on another phone).

 

[B. Diddy]

Which phone, and which carrier? Give us the exact brand and model name/number of the phone.

 

[FAHMI BASSEM]

Nokia 9 Ta-1087, Umniah is the carrier.

 

[belodion]

Nokia 9 Ta-1087, Umniah is the carrier.

That's a global model, so ought to work. Did the carrier suggest a replacement SIM? Have you tried using someone else's SIM, or tried your SIM in another phone?

 

[B. Diddy]

Go to Settings>Mobile Networks, and look for an option for Preferred Network Type. What's selected currently?

 

[FAHMI BASSEM]

I'm having a replacement today, will reply as soon as I try

Thanks!

That's a global model, so ought to work. Did the carrier suggest a replacement SIM? Have you tried using someone else's SIM, or tried your SIM in another phone?

 

[FAHMI BASSEM]

Set for 4G (Recommended), I also tried manual selection for network, didn't work ,

Go to Settings>Mobile Networks, and look for an option for Preferred Network Type. What's selected currently?

 

[FAHMI BASSEM]

I'm having a replacement today, will reply as soon as I try

Thanks!

Nope, the new SIM solution did not work

 

[FAHMI BASSEM]

New finding:
Switched the data to 3G (H+), and everything works perfectly!

The question is why?

Thanks...

 

[B. Diddy]

Maybe when it's set to 4G, the phone is trying to use 4G for calls as well, but the carrier doesn't support it? Another possible workaround would be to turn off VoLTE on the phone, if it's on.

 

[Rukbat]

Another possibility is that where you are there's only a weak 4G signal, but a strong 3G signal. (There's a separate transmitter for each one, and there may not be any 4G transmitters near you.)

 

[FAHMI BASSEM]

Will for look for the Volte option and turn it off, Tha KS for the suggestion!

 

[FAHMI BASSEM]

Another possibility is that where you are there's only a weak 4G signal, but a strong 3G signal. (There's a separate transmitter for each one, and there may not be any 4G transmitters near you.)

Well, my old phone works just fine, same area same operator...

Thanks for the explanation!

 

[B. Diddy]

Will for look for the Volte option and turn it off, Tha KS for the suggestion!

The option is usually in the Settings>Mobile Networks menu, possibly under Advanced Options.