added comments

bigbluebutton-html5/imports/ui/components/components-data/chat-context/adapter.jsx

@@ -64,6 +64,8 @@ const Adapter = () => {
 
   useEffect(() => {
     window.addEventListener(EVENT_NAME, () => {
+      /* needed to prevent an issue with dupĺicated messages when user role is changed
+      more info: https://github.com/bigbluebutton/bigbluebutton/issues/11842 */
       if (prevUserData.role && prevUserData?.role !== currentUserData?.role) {
         dispatch({
           type: ACTIONS.CLEAR_STREAM_MESSAGES,
@@ -82,6 +84,8 @@ const Adapter = () => {
   }, [Meteor.status().connected, syncStarted, Auth.userID]);
 
 
+  /* needed to prevent an issue with dupĺicated messages when user role is changed
+  more info: https://github.com/bigbluebutton/bigbluebutton/issues/11842 */
   useEffect(() => {
     if (users[Auth.meetingID]) {
       if (currentUserData?.role !== users[Auth.meetingID][Auth.userID].role) {