Dual sim system keep force restarting

[Tataandmomo]

I have 2 sim card and travel between 2 cities.

I have used X3+, XZ, XZs, XZ2 compact (current). And for all these phones , it happens to keep forcing me to use Sim 2 for mobile data when I selected Sim 1. This happened 4 times today already, and I keep restarting my phone all day ! And similar situation happened to all my previous phone since dual sim phone is available. Every time I email to Sony support, they just ask me to restore my phone and tell me this is the first time they heard about this. But I have had the same problem and emailed several times already. I just wonder if this is a bug in Sony dual sim phone.

Can anybody help? I have used over 10 Sony /Sony Ericsson phones already, I don't want to switch to other brand. 

[NunoSEN2]

Hi @Tataandmomo ;

 I never had one of the phones you described but I have always used Dual SIM phones (M,M2,Z3,Z5 and now XZ Premium) and always use mainly SIM 1 for data with a very occasionally change to SIM2 and never the phone forced me or changed the SIM I choosed for data. 

I can see from your screenshot that you are using one of the SIM cards in Roaming, do you have by any chance data in Roaming activated for both of the SIM cards? You also use VoLTE, is it on the same SIM card you want to use for data? Don't know if any of it can be the cause as I never used them but you can test it.

[Tataandmomo]

Yes, Sim 2 is mostly roaming. And the phone keep forcing me to use it for data! Lucky that SIM card do not have a roaming data plan.

(I get Sim 1 from city A; while Sim 2 from city B. I travel between these 2 cities.)

I’m so frastrated that it keep picking the roaming card for data! I once thought it’s the SIM card problem and go to the service provider to get a new card.

[Jornschol]

I'm having the same issue!