Hi @Am57 and welcome to the community,
I'm sorry for the late reply. What happens when you try to pair your Xperia device with another phone? Do you get a error message? Is it possible to pair your device with any Bluetooth device?
I would also recommend that you reboot your device to safe mode to see if this behavior is caused by one of your downloaded apps as these will be temporarily disabled in this mode.
Let me know how it goes.
