I've had Sony's for years and years though and never had a Bluetooth problem with any of them, including my previous phone which was also an XZ3. This one I have now is a replacement phone due to a totally unrelated fault with the previous one.
The devices it's not finding are headphones and earphones, so all they have is an on/off button and volume/skip track buttons, no button for visibility, plus these relatively new headphones connected more or less instantly with ease and no issues with my previous XZ3, as did my earphones which I've had for about 3 years now. All that leads me to believe headphones/earphones are always visible as standard? Either way, my XZ3 isn't finding them and that's while they're less than a metre apart.
I've also seen another tip somewhere to try getting the Bluetooth connection going by first trying with NFC, but there's no NFC symbol/point on my headphones or earphones.
