I own a Sony XPeria Z3 Dual (D6633) and I have two active SIM cards (Operator1 - OP1 and Operator2 - OP2). I'm using this phone with this setting for more than 6 months without any problem until last week when my OP1 SIM has gone away, that is, the phone began to report that there was not inserted SIM, but I do not saw any automatic reboot notification, that normally occurs when one SIM card is removed.
Thinking to be an Android problem, I just reboot the phone and the OP1 SIM appeared as expected. A few hours later the OP1 SIM disappeared again, then I started to think it was a problem on SIM's slot and, to end this doubt, I turned off the phone and changed the SIM positions, i.e., OP1 SIM is now on OP2 SIM slot and vice-versa.
After turn on the cellphone the two SIM were active / visible, but a few hours later, again, the OP1 SIM disappeared. I thought the obvious: a problematic SIM card. Then I went to a OP1 store and I bought a new SIM card and put it on the phone. Everything was working as it should, until the next day, wen, one more time the OP1 SIM disappeared!. This time, even after restarting the phone, it appears, and a few seconds later it disappear.
I bought another SIM card, from another mobile operator and until now this SIM card is working on my D6633 together with my another SIM card (OP2).
Meanwhile I put the OP1 SIM card on another cellphone (an old cellphone, not a smartphone), and this old cellphone is working with the OP1 SIM card without problem!!
After all this report, what I can do? I really like the OP1, but my D6633 seems to not like it anymore. Someone has some tip to me? What is the REAL problem?
