The first worked after a bit of learning, and every subsequent worked first time.
If you know what you are doing, which is quite clearly not the case, you would know already that the HC-05 works essentially the same as all the other bluetooth devices you have. There is nothing special about it, hence the previous conclusion that you are the problem.
There is indeed a faint possibility that the device is faulty, but it is unlikely, and there is nothing that you have said that might suggest that - and quite a lot to suggest it isn't. All you have done is blame your incompetence on a device that is probably entirely innocent - and also renowned for its simplicity and reliability.