Update docs/release-notes/8.19.asciidoc

Co-authored-by: Gabriel Landau <[email protected]>

Author: nastasha-solomon

docs/release-notes/8.19.asciidoc

@@ -16,7 +16,8 @@
 [discrete]
 [[bug-fixes-8.19.2]]
 ==== Fixes
-* Fixes a bug where Linux endpoint network events would fail to load if IPV6 is not supported by the system.
+* Due to an issue in macOS, {elastic-defend} would sometimes send network events without `user.name` populated. {elastic-defend} will now identify these events and populate `user.name` if necessary
+* Fixes an issue in {elastic-defend} performance metrics that resulted in `endpoint_uptime_percent` always being 0 for behavioral rules.
 
 [discrete]
 [[release-notes-8.19.1]]