initialScrollIndex not work !

[mwlt68]

When i pass value from list count it don't scroll. It show first item and no error.

Expanded _bodyMessages(ChatState state) {
    var messageCount = state.messages.length;
    var model = Expanded(
      child: StickyGroupedListView<ConversationMessageModel, DateTime>(
        elements: state.messages,
        order: StickyGroupedListOrder.ASC,
        groupBy: (ConversationMessageModel element) => DateTime(
          element.createdAt!.year,
          element.createdAt!.month,
          element.createdAt!.day,
        ),
        groupComparator: (DateTime value1, DateTime value2) =>
            value1.compareTo(value2),
        itemComparator: (ConversationMessageModel element1,
                ConversationMessageModel element2) =>
            element1.createdAt!.compareTo(element2.createdAt!),
        floatingHeader: true,
        groupSeparatorBuilder: _getGroupSeparator,
        indexedItemBuilder: (context, element, index) =>
            _getItem(element, index, state.messages.length, state.currentUser!),
        itemScrollController: _scrollController,
        initialScrollIndex: messageCount,
      ),
   
);

    return model;
  }

When i give initialScrollIndex as digit it scroll but give an error !

initialScrollIndex: 5,

══╡ EXCEPTION CAUGHT BY WIDGETS LIBRARY ╞═══════════════════════════════════════════════════════════
The following assertion was thrown building LayoutBuilder:
'package:scrollable_positioned_list/src/positioned_list.dart': Failed assertion: line 49 pos 16:
'(positionedIndex == 0) || (positionedIndex < itemCount)': is not true.

The relevant error-causing widget was:
LayoutBuilder
LayoutBuilder:file:///home/mevlut/.pub-cache/hosted/pub.dev/scrollable_positioned_list-0.3.8/lib/src/scrollable_positioned_list.dart:408:12

When the exception was thrown, this was the stack:
#2 new PositionedList (package:scrollable_positioned_list/src/positioned_list.dart:49:16)
#3 _ScrollablePositionedListState.build. (package:scrollable_positioned_list/src/scrollable_positioned_list.dart:422:28)
#4 _LayoutBuilderElement._layout.layoutCallback (package:flutter/src/widgets/layout_builder.dart:119:77)
#5 BuildOwner.buildScope (package:flutter/src/widgets/framework.dart:2682:19)
#6 _LayoutBuilderElement._layout (package:flutter/src/widgets/layout_builder.dart:153:12)
#7 RenderObject.invokeLayoutCallback. (package:flutter/src/rendering/object.dart:2300:59)
#8 PipelineOwner._enableMutationsToDirtySubtrees (package:flutter/src/rendering/object.dart:1056:15)
#9 RenderObject.invokeLayoutCallback (package:flutter/src/rendering/object.dart:2300:14)
#10 RenderConstrainedLayoutBuilder.rebuildIfNecessary (package:flutter/src/widgets/layout_builder.dart:228:7)
#11 _RenderLayoutBuilder.performLayout (package:flutter/src/widgets/layout_builder.dart:313:5)
#12 RenderObject.layout (package:flutter/src/rendering/object.dart:2189:7)
#13 RenderBox.layout (package:flutter/src/rendering/box.dart:2430:11)
#14 ChildLayoutHelper.layoutChild (package:flutter/src/rendering/layout_helper.dart:56:11)
#15 RenderStack._computeSize (package:flutter/src/rendering/stack.dart:595:43)
#16 RenderStack.performLayout (package:flutter/src/rendering/stack.dart:622:12)
#17 RenderObject.layout (package:flutter/src/rendering/object.dart:2189:7)
#18 RenderBox.layout (package:flutter/src/rendering/box.dart:2430:11)
#19 ChildLayoutHelper.layoutChild (package:flutter/src/rendering/layout_helper.dart:56:11)
#20 RenderFlex._computeSizes (package:flutter/src/rendering/flex.dart:903:45)
#21 RenderFlex.performLayout (package:flutter/src/rendering/flex.dart:938:32)
#22 RenderObject.layout (package:flutter/src/rendering/object.dart:2189:7)
#23 RenderBox.layout (package:flutter/src/rendering/box.dart:2430:11)
#24 RenderConstrainedBox.performLayout (package:flutter/src/rendering/proxy_box.dart:297:14)
#25 RenderObject.layout (package:flutter/src/rendering/object.dart:2189:7)
#26 RenderBox.layout (package:flutter/src/rendering/box.dart:2430:11)
#27 MultiChildLayoutDelegate.layoutChild (package:flutter/src/rendering/custom_layout.dart:171:12)
#28 _ScaffoldLayout.performLayout (package:flutter/src/material/scaffold.dart:1080:7)
#29 MultiChildLayoutDelegate._callPerformLayout (package:flutter/src/rendering/custom_layout.dart:240:7)
#30 RenderCustomMultiChildLayoutBox.performLayout (package:flutter/src/rendering/custom_layout.dart:410:14)
#31 RenderObject.layout (package:flutter/src/rendering/object.dart:2189:7)
#32 RenderBox.layout (package:flutter/src/rendering/box.dart:2430:11)
#33 RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:120:14)
#34 RenderObject.layout (package:flutter/src/rendering/object.dart:2189:7)
#35 RenderBox.layout (package:flutter/src/rendering/box.dart:2430:11)
#36 RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:120:14)
#37 _RenderCustomClip.performLayout (package:flutter/src/rendering/proxy_box.dart:1467:11)
#38 RenderObject.layout (package:flutter/src/rendering/object.dart:2189:7)
#39 RenderBox.layout (package:flutter/src/rendering/box.dart:2430:11)
#40 RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:120:14)
#41 RenderObject.layout (package:flutter/src/rendering/object.dart:2189:7)
#42 RenderBox.layout (package:flutter/src/rendering/box.dart:2430:11)
#43 RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:120:14)
#44 RenderObject.layout (package:flutter/src/rendering/object.dart:2189:7)
#45 RenderBox.layout (package:flutter/src/rendering/box.dart:2430:11)
#46 RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:120:14)
#47 RenderObject.layout (package:flutter/src/rendering/object.dart:2189:7)
#48 RenderBox.layout (package:flutter/src/rendering/box.dart:2430:11)
#49 RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:120:14)
#50 RenderObject.layout (package:flutter/src/rendering/object.dart:2189:7)
#51 RenderBox.layout (package:flutter/src/rendering/box.dart:2430:11)
#52 RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:120:14)
#53 RenderObject.layout (package:flutter/src/rendering/object.dart:2189:7)
#54 RenderBox.layout (package:flutter/src/rendering/box.dart:2430:11)
#55 RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:120:14)
#56 RenderObject.layout (package:flutter/src/rendering/object.dart:2189:7)
#57 RenderBox.layout (package:flutter/src/rendering/box.dart:2430:11)
#58 RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:120:14)
#59 RenderObject.layout (package:flutter/src/rendering/object.dart:2189:7)
#60 RenderBox.layout (package:flutter/src/rendering/box.dart:2430:11)
#61 RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:120:14)
#62 RenderObject.layout (package:flutter/src/rendering/object.dart:2189:7)
#63 RenderBox.layout (package:flutter/src/rendering/box.dart:2430:11)
#64 RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:120:14)
#65 RenderObject.layout (package:flutter/src/rendering/object.dart:2189:7)
#66 RenderBox.layout (package:flutter/src/rendering/box.dart:2430:11)
#67 RenderOffstage.performLayout (package:flutter/src/rendering/proxy_box.dart:3813:14)
#68 RenderObject.layout (package:flutter/src/rendering/object.dart:2189:7)
#69 RenderBox.layout (package:flutter/src/rendering/box.dart:2430:11)
#70 RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:120:14)
#71 RenderObject.layout (package:flutter/src/rendering/object.dart:2189:7)
#72 RenderBox.layout (package:flutter/src/rendering/box.dart:2430:11)
#73 _RenderTheatre.performLayout (package:flutter/src/widgets/overlay.dart:856:15)
#74 RenderObject._layoutWithoutResize (package:flutter/src/rendering/object.dart:2027:7)
#75 PipelineOwner.flushLayout (package:flutter/src/rendering/object.dart:1020:18)
#76 RendererBinding.drawFrame (package:flutter/src/rendering/binding.dart:516:19)
#77 WidgetsBinding.drawFrame (package:flutter/src/widgets/binding.dart:865:13)
#78 RendererBinding._handlePersistentFrameCallback (package:flutter/src/rendering/binding.dart:381:5)
#79 SchedulerBinding._invokeFrameCallback (package:flutter/src/scheduler/binding.dart:1289:15)
#80 SchedulerBinding.handleDrawFrame (package:flutter/src/scheduler/binding.dart:1218:9)
#81 SchedulerBinding._handleDrawFrame (package:flutter/src/scheduler/binding.dart:1076:5)
#82 _invoke (dart:ui/hooks.dart:145:13)
#83 PlatformDispatcher._drawFrame (d

art:ui/platform_dispatcher.dart:338:5)
#84 _drawFrame (dart:ui/hooks.dart:112:31)
(elided 2 frames from class _AssertionError)