You may need to clear paired history of Priva III if it is not working as expected, such as audio cut in and out, short range, not pairing...
Clear Paired History of Priva III:
Step 1: Get Priva III into pairing mode - press and hold MFB for 1 second until LED flashes BLUE and RED alternately. Then let go of MFB.
Step 2: Press and hold MFB button for 5s, then BLUE LED is on for 2 seconds.
Step 3: It will enter paring mode automatically, and LEDs on Priva III flashes BLUE and RED alternately.
You may also refer to this video for detail instructions: