The simplest possible solution you can try first would be a soft reset on the phone. This helps clear minor software glitches that may have caused network conflicts and minor Wi-Fi problems on the phone. Here’s how to perform a soft reset on your Xperia XZ3 smartphone:
Press and hold down thePower buttonfor a few seconds and then release when the menu opens.
Your phone then restarts automatically.
Alternatively, you can force your phone to restart by pressing and holding down the Power button and the Volume Up button simultaneously for about 6 seconds. diebestetest When your phone vibrates, release the buttons. Your phone then restarts.