Your Windows 10 Bluetooth audio issues may be due to Cumulative Update KB4505903

Windows 10 update KB4505903 for the May 2019 PC update was released on July 26th as an optional cumulative update.  The update mostly went smoothly, apart from DPC latency issues, which Microsoft released a fix for in the next cumulative update.

Since then, however, more issues have surfaced.  A new support doc by Microsoft outlines the Bluetooth functionality issues users are experiencing with the Windows 10 KB4505903 update on their PC.

Users have found that upon “successful” Bluetooth connection, the audio output source will still remain as the internal speaker.  Those who managed to successfully connect found they were met with poor sound quality.

This is what one user had to say on the Microsoft Feedback Hub:

After installing latest Windows 10 1903 quality update KB4505903 (July 2019) Intel Bluetooth Adapter was completely removed from system and could not be reinstalled or reactivated

The user found that uninstalling the patch was enough to resolve the Bluetooth issue.  Alternatively, Microsoft is advising users to run the System File Checker tool to repair corrupted Windows files:

• Open Command Prompt (CMD) with Administrative privileges.
• Type the following command and press enter:

sfc /scannow

• Reboot system.

The latest update to Windows Defender includes a fix for SFC command, so it’s essential to have the latest defender security patches installed.

Source: windowslatest 

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