Xperia Z3 :: Missed Calls And Text When In Sleep Mode

When my phone is in sleep mode, I do not receive calls or text. I have a unlocked Z3 (model D6603).  I have tested the problem with stamina mode on and off.  No difference. In my testing, the phone works 100% of the time when awake, but when sleeping, in the same location, the calls are never received. I asked sony about this, and as always, they suggest run through pc repair, which won't work on unlocked phone.  This wont work on unlocked phone. I have done factory resets and it has not worked.