Share your experience!
i have xperia z5 premium dual after i turn on the device i see every time the mobile data On i must turn off by my self ,,, turn off the device again and turn on the mobile data turn on again !
what can i do to make it off always ??
i bought it from 3 days ago it was have lollipop 5.1.1 and i updated it the latest firmware 6.0 from the About Phone
sorry for my english
That's Screenshot
Guys what can i do now
i changed the firmware to Customized MEA and the same problem : Mobile Data turn on always 
I'm sorry to hear that.
We have found the cause for this and it will be fixed in an upcoming software update. It's not certain the fix will make it into the update that is coming next though.

An update is planned to be released next month but i'm afraid it's not certain the fix for this will make it into this update. Also note that software updates rollouts are a phased process – timings & availability may vary by market/carrier.
I'm afraid it's not possible for me to see whe the update will be released for a certain country or operator.
I'm not sure why that setting is not saved when you restart the phone, i'll see if i can find more information about it.
I'm afraid i've not been able to find the background for why the "Allow peeking" setting is reset at restart. It's not specific for Z5, it seems to be standard for Android as i see the same thing when i test this in a Nexus phone.