In an update to the support bulletin for the Windows 10 1903 KB4515384 cumulative update, Microsoft has acknowledged that a change was made that would cause games to sound different or have low volume.

Since the Windows 10 1903 KB4515384 update was released last Tuesday, Windows 10 users have been reporting that the sound in games has been very low, muffled, or just strange This problem has been reported for games such as Overwatch, Apex Legends, WoW Classic, and PlayerUnknown's Battlegrounds (PUBG).

In an update to their support bulletin, Microsoft stated that at the request of audio hardware manufacturers they implemented a change that may cause games to sound different or have missing channels, which reduces audio volume or makes it sound muffled.

"Microsoft has received reports that audio in certain games is quieter or different than expected after installing this update. At the request of some of our audio partners, we implemented a compatibility change that enabled certain games to query support and render multi-channel audio. Due to customer feedback, we are reverting this change as some games and some devices are not rendering multi-channel audio as expected. This may result in games sounding different than customers are used to and may have missing channels."

To resolve this issue, Microsoft plans on reverting the change in the next cumulative update being released at the end of September.

Until then, Microsoft has provided the following temporary workaround that can be used in certain games to make them sound normal again.

"To mitigate the issue, open settings in the impacted game and disable multi-channel audio, if this option is available. You can also search in the Windows Control Panel for third-party audio device control panels and disable Multi-channel audio or Virtual Surround Sound, if these options are available. We are working on a resolution and estimate a solution will be available in late September."

BleepingComputer could not find this setting in games like PUBG or Fortnite, so if this bug is affecting those games, you should try to resolve it in your sound card's control panel or audio properties if available.