The problem with unstable Wi-Fi had not come from Android 7.0!! I suffered it with initial Android 5 and then 6. I applied to any kind of so called Xperia care WITH NO RESULT AL ALL! Wifi is working occasionally that means the hardware is good and the is no problem they say. For software they recommend to claim for Google.
As the problem is, and it s been coming from manufacture, and Japanese company does nothing to save it's high reputation, saying to recall or exchange phones for new properly working the only way out is to change the brand, although I always used Sony. I am still waiting and then say goodbye Sony forever!
