https://wccftech.com/just-released-windows-10-may-2021-update-known-issues/

Microsoft has started delivering Windows 10 May 2021 Update to devices running version 2004 or 20H2. The feature update is also available via ISO files that help you skip the line. However, the company has already reported two known issues affecting version 21H1. The good news is that both have mitigations available, which means no safeguard hold has been put in place (as yet).

1- A high-pitched noise might be heard when using 5.1 audio with certain settings (Tagged as Mitigated)