Difference between Error code 814 and 506

What is the difference between error code 814 and 506. Both show the description : To pair the devices you have to be in Bluetooth range.

506 is a general Bluetooth error (connection lost) while 814 is an Android specific one which could hint on a problem with your devices Bluetooth stack, where a restart of your Bluetooth could help.
In general it is a good idea to restart bluetooth on your device if you get these errors.
But the codes are mainly here for our support to help you debug. Real problems can best be checked in the App debug log if the problem resists after restarting Bluetooth.