Add Known Issues.

astro/src/content/docs/release-notes/index.mdx

@@ -37,6 +37,10 @@ Looking for release notes older than 1.23.0? Look in the [release notes archive]
 
 <ReleaseNoteHeading version='1.53.0' releaseDate='September 5, 2024' name='Lambda Llama'/>
 
+### Known Issues
+* A user may fail to enroll a new Passkey (WebAuthn credential) used for reauthentication during a login workflow. Previously configured Passkeys should continue to work as expected.
+  * Tracking via [GitHub Issue #2861](https://github.com/FusionAuth/fusionauth-issues/issues/2861)
+
 ### Changed
 * The Docker image for the `linux/arm/v7` architecture is not being published for this release.