Merge pull request #96418 from openshift-cherrypick-robot/cherry-pick-95990-to-enterprise-4.15

[enterprise-4.15] OBSDOCS-1916: known-issue Logging Z-Stream Release Notes - 5.9.15

Author: ShaunaDiaz

modules/logging-release-notes-5-9-15.adoc

@@ -22,4 +22,9 @@ This release includes link:https://access.redhat.com/errata/RHBA-2025:8775[RHBA-
 [NOTE]
 ====
 For detailed information on Red{nbsp}Hat security ratings, review link:https://access.redhat.com/security/updates/classification/#low[Severity ratings].
-====
+====
+
+[id="known-issues-5-9-15_{context}"]
+== Known issues
+
+* When you forward logs to a syslog output, the produced message format is inconsistent between Fluentd and Vector log collectors. Vector messages are within quotation marks; Fluentd messages are not. As a consequence, when migrating from Fluentd to Vector, users might experience issues with their tool integrations.  (link:https://issues.redhat.com/browse/LOG-7007[LOG-7007])