[Q] Bluetooth Voice Dialing problem

[R0YB0T]

Pressing and holding the main button on my BT headset won't initiate voice dialing unless my screen is on and unlocked.
Double tapping the button redials the last call even if it is locked.

This combined with the lack of confirmation before dialing makes this feature next to useless.

My headset is a Plantronics Voyager Pro and I have tested it with a second Plantronics Voyager Pro.