Microsoft is aware of reports that the Absolute Volume feature is incompatible with some Bluetooth devices, resulting in the inability to adjust the Bluetooth device’s volume. If you are experiencing this issue, neither the volume slider in the taskbar, nor the device’s volume controls have any effect on volume.
To resolve this issue, first make sure you’ve installed the latest Windows Updates. A solution was included in the October 24, 2018—KB4462933 (OS Build 17134.376) update for Windows 10 version 1803. To check for updates, select the Start button, and then go to Settings> Update & security> Windows Update, and select Check for updates.
Three devices that are known to experience the issue will automatically have the Absolute Volume feature disabled and should no longer experience the issue once you’ve installed KB4462933: Creative T30 Wireless Speakers, Edifier R2000 DB, and the JBL Go.
For other Bluetooth devices, once you’ve installed KB4462933 or once you've installed Windows 10 version 1809, you can resolve the issue by disabling Absolute Volume manually by making a change in the registry. (Warning: Serious problems might occur if you modify the registry incorrectly. For added protection, back up the registry before attempting to modify it.)
To disable the Absolute Volume feature manually:
1. In the Search box, type cmd. Right-click Command Prompt in the Search results and select Run as administrator.
2. In the Command Prompt window, type the following command:
reg add HKLM\SYSTEM\ControlSet001\Control\Bluetooth\Audio\AVRCP\CT /v DisableAbsoluteVolume /t REG_DWORD /d 1 /f
To re-enable the Absolute Volume feature:
1. In the Search box, type cmd. Right-click Command Prompt in the Search results and select Run as administrator.
2. In the Command Prompt window, type the following command:
reg add HKLM\SYSTEM\ControlSet001\Control\Bluetooth\Audio\AVRCP\CT /v DisableAbsoluteVolume /t REG_DWORD /d 0 /f
You may need to restart Windows for the registry change to take effect.