[Simple]

Actually, it is not a matter of luck, the working combinations of Firmware/Revision are known, what I wrote above is the rule of thumb. It is a matter of luck to the buyer of the Chinese clone who is not sure of his equipment until he gets it.

Try flashing your desirable Firmware then connecting the device after starting DiagBox, or you could inject your desirable Firmware by replacing C:\AWRoot\bin\launcher\appli.com with the version you like and start DiagBox while the device is connected!!

However, being able to connect and to perform reliable diagnosis are two different things, this is why there has been numerous updates, to account for bug fixes and/or new functionality. At the end of the day, it is what works for you..