fix(ui): add initialIndex and alignment to didUpdateWidget in scrollable list

packages/stream_chat_flutter/lib/src/message_list_view.dart

@@ -353,20 +353,6 @@ class _MessageListViewState extends State<MessageListView> {
   MessageListController get _messageListController =>
       widget.messageListController ?? _defaultController;
 
-  @override
-  void didUpdateWidget(MessageListView oldWidget) {
-    super.didUpdateWidget(oldWidget);
-    if (widget.initialScrollIndex != oldWidget.initialScrollIndex ||
-        widget.initialAlignment != oldWidget.initialAlignment) {
-      initialIndex = _initialIndex;
-      initialAlignment = _initialAlignment;
-      _scrollController?.jumpTo(
-        index: initialIndex,
-        alignment: initialAlignment,
-      );
-    }
-  }
-
   @override
   Widget build(BuildContext context) => MessageListCore(
         paginationLimit: widget.paginationLimit,
@@ -1255,14 +1241,12 @@ class _MessageListViewState extends State<MessageListView> {
       initialIndex = _initialIndex;
       initialAlignment = _initialAlignment;
 
-      WidgetsBinding.instance!.addPostFrameCallback((timeStamp) {
+      if (_scrollController?.isAttached == true) {
-        if (_scrollController?.isAttached == true) {
+        _scrollController?.jumpTo(
-          _scrollController?.jumpTo(
+          index: initialIndex,
-            index: initialIndex,
+          alignment: initialAlignment,
-            alignment: initialAlignment,
+        );
-          );
+      }
-        }
-      });
 
       _messageNewListener =
           streamChannel!.channel.on(EventType.messageNew).listen((event) {

packages/stream_chat_flutter/lib/src/scrollable_positioned_list/src/scrollable_positioned_list.dart

@@ -325,6 +325,14 @@ class _ScrollablePositionedListState extends State<ScrollablePositionedList>
         secondary.target = widget.itemCount - 1;
       }
     }
+
+    if (widget.initialScrollIndex != oldWidget.initialScrollIndex ||
+        widget.initialAlignment != oldWidget.initialAlignment) {
+      _jumpTo(
+        index: widget.initialScrollIndex,
+        alignment: widget.initialAlignment,
+      );
+    }
   }
 
   @override