Null check operator used on a null value

[heafox]

Describe the bug
A clear and concise description of what the bug is.

════════ Exception caught by widgets library ═══════════════════════════════════
The following _TypeError was thrown building GroupedListView<Device, DeviceType>(dirty, state: _GroupedListViewState<Device, DeviceType>#01414):
Null check operator used on a null value

The relevant error-causing widget was:
GroupedListView<Device, DeviceType> GroupedListView:file:///C:/Users/94093/Documents/hpc/over_ip_pad/lib/settings/device_control_view.dart:27:26

When the exception was thrown, this was the stack:
#0 _GroupedListViewState._sortElements. (package:grouped_list/grouped_list.dart:509:29)
grouped_list.dart:509
#1 Sort._insertionSort (dart:_internal/sort.dart:69:36)
sort.dart:69
#2 Sort._doSort (dart:_internal/sort.dart:58:7)
sort.dart:58
#3 Sort.sort (dart:_internal/sort.dart:33:5)
sort.dart:33
#4 ListBase.sort (dart:collection/list.dart:321:10)
list.dart:321
#5 _GroupedListViewState._sortElements (package:grouped_list/grouped_list.dart:491:16)
grouped_list.dart:491
#6 _GroupedListViewState.build (package:grouped_list/grouped_list.dart:312:23)
grouped_list.dart:312
#7 StatefulElement.build (package:flutter/src/widgets/framework.dart:5729:27)
framework.dart:5729
#8 ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:5617:15)
framework.dart:5617
#9 StatefulElement.performRebuild (package:flutter/src/widgets/framework.dart:5780:11)
framework.dart:5780
#10 Element.rebuild (package:flutter/src/widgets/framework.dart:5333:7)
framework.dart:5333
#11 ComponentElement._firstBuild (package:flutter/src/widgets/framework.dart:5599:5)
framework.dart:5599
#12 StatefulElement._firstBuild (package:flutter/src/widgets/framework.dart:5771:11)
framework.dart:5771
#13 ComponentElement.mount (package:flutter/src/widgets/framework.dart:5593:5)
framework.dart:5593
#14 Element.inflateWidget (package:flutter/src/widgets/framework.dart:4468:16)
framework.dart:4468
#15 Element.updateChild (package:flutter/src/widgets/framework.dart:3957:20)
framework.dart:3957
#16 ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:5642:16)
framework.dart:5642
#17 StatefulElement.performRebuild (package:flutter/src/widgets/framework.dart:5780:11)
framework.dart:5780
#18 Element.rebuild (package:flutter/src/widgets/framework.dart:5333:7)
framework.dart:5333
#19 BuildScope._tryRebuild (package:flutter/src/widgets/framework.dart:2693:15)
framework.dart:2693
#20 BuildScope._flushDirtyElements (package:flutter/src/widgets/framework.dart:2752:11)
framework.dart:2752
#21 BuildOwner.buildScope (package:flutter/src/widgets/framework.dart:3048:18)
framework.dart:3048
#22 WidgetsBinding.drawFrame (package:flutter/src/widgets/binding.dart:1162:21)
binding.dart:1162
#23 RendererBinding._handlePersistentFrameCallback (package:flutter/src/rendering/binding.dart:468:5)
binding.dart:468
#24 SchedulerBinding._invokeFrameCallback (package:flutter/src/scheduler/binding.dart:1397:15)
binding.dart:1397
#25 SchedulerBinding.handleDrawFrame (package:flutter/src/scheduler/binding.dart:1318:9)
binding.dart:1318
#26 SchedulerBinding._handleDrawFrame (package:flutter/src/scheduler/binding.dart:1176:5)
binding.dart:1176
#27 _invoke (dart:ui/hooks.dart:312:13)
hooks.dart:312
#28 PlatformDispatcher._drawFrame (dart:ui/platform_dispatcher.dart:419:5)
platform_dispatcher.dart:419
#29 _drawFrame (dart:ui/hooks.dart:283:31)
hooks.dart:283

Expected behavior
A clear and concise description of what you expected to happen.

I don't want the list to be reordered

Information:

• Dart version: 3.5
• Flutter version: 3.24.3
• Platform: Windows 11
• Package version: 6.0.0