diff --git a/packages/devtools_app/lib/src/screens/inspector/inspector_data_models.dart b/packages/devtools_app/lib/src/screens/inspector/inspector_data_models.dart
index 482c214c27b..89d4f52405e 100644
--- a/packages/devtools_app/lib/src/screens/inspector/inspector_data_models.dart
+++ b/packages/devtools_app/lib/src/screens/inspector/inspector_data_models.dart
@@ -96,7 +96,7 @@ List<double> computeRenderSizes({
 class LayoutProperties {
   LayoutProperties(this.node, {int copyLevel = 1})
       : description = node.description,
-        size = node.size,
+        size = node.size!,
         constraints = node.constraints,
         isFlex = node.isFlex,
         flexFactor = node.flexFactor,
diff --git a/packages/devtools_app/lib/src/screens/inspector_v2/inspector_data_models.dart b/packages/devtools_app/lib/src/screens/inspector_v2/inspector_data_models.dart
index f81658f4033..87972187506 100644
--- a/packages/devtools_app/lib/src/screens/inspector_v2/inspector_data_models.dart
+++ b/packages/devtools_app/lib/src/screens/inspector_v2/inspector_data_models.dart
@@ -119,7 +119,7 @@ enum SizeType {
 class LayoutProperties {
   LayoutProperties(this.node, {int copyLevel = 1})
       : description = node.description,
-        size = node.size,
+        size = node.size!,
         constraints = node.constraints,
         isFlex = node.isFlex,
         flexFactor = node.flexFactor,
@@ -246,7 +246,7 @@ class LayoutProperties {
     if (parentElement == null) return this;
     final parentProperties =
         parentElement.computeLayoutProperties(forFlexLayout: false);
-    return parentProperties;
+    return parentProperties ?? this;
   }
 
   WidgetSizes? get widgetWidths => _widgetSizes(SizeType.widths);
diff --git a/packages/devtools_app/lib/src/screens/inspector_v2/widget_properties/properties_view.dart b/packages/devtools_app/lib/src/screens/inspector_v2/widget_properties/properties_view.dart
index 08b88444e9f..f8d826c426d 100644
--- a/packages/devtools_app/lib/src/screens/inspector_v2/widget_properties/properties_view.dart
+++ b/packages/devtools_app/lib/src/screens/inspector_v2/widget_properties/properties_view.dart
@@ -136,8 +136,7 @@ class _PropertiesViewState extends State<PropertiesView> {
   RemoteDiagnosticsNode? get selectedNode =>
       widget.controller.selectedNode.value?.diagnostic;
 
-  bool get includeLayoutExplorer =>
-      (selectedNode?.isBoxLayout ?? false) && widget.layoutProperties != null;
+  bool get includeLayoutExplorer => widget.layoutProperties != null;
 
   WidgetSizes? get widgetWidths => widget.layoutProperties?.widgetWidths;
 
diff --git a/packages/devtools_app/lib/src/shared/diagnostics/diagnostics_node.dart b/packages/devtools_app/lib/src/shared/diagnostics/diagnostics_node.dart
index 2a5a32fcd54..2e2478dec18 100644
--- a/packages/devtools_app/lib/src/shared/diagnostics/diagnostics_node.dart
+++ b/packages/devtools_app/lib/src/shared/diagnostics/diagnostics_node.dart
@@ -153,9 +153,12 @@ class RemoteDiagnosticsNode extends DiagnosticableTree {
   // [deserializeSize] expects a parameter of type Map<String, Object> (note the
   // non-nullable Object), so we need to first type check as a Map and then we
   // can cast to the expected type.
-  Size get size => deserializeSize(
-        (json['size'] as Map?)?.cast<String, Object>() ?? <String, Object>{},
-      );
+  Size? get size {
+    final sizeMap = json['size'] as Map?;
+    return sizeMap == null
+        ? null
+        : deserializeSize(sizeMap.cast<String, Object>());
+  }
 
   bool get isLocalClass {
     final objectGroup = objectGroupApi;
@@ -454,16 +457,17 @@ class RemoteDiagnosticsNode extends DiagnosticableTree {
     return json[memberName] as bool;
   }
 
-  LayoutProperties computeLayoutProperties({required bool forFlexLayout}) {
-    assert(!forFlexLayout || (forFlexLayout && isFlexLayout));
+  LayoutProperties? computeLayoutProperties({required bool forFlexLayout}) {
+    if ((!forFlexLayout && !isBoxLayout) || (forFlexLayout && !isFlexLayout)) {
+      return null;
+    }
     return forFlexLayout
         ? FlexLayoutProperties.fromDiagnostics(this)
         : LayoutProperties(this);
   }
 
   RemoteDiagnosticsNode? layoutRootNode({required bool forFlexLayout}) {
-    final shouldDisplayNode = forFlexLayout ? isFlexLayout : isBoxLayout;
-    if (!shouldDisplayNode) return null;
+    if (forFlexLayout && !isFlexLayout) return null;
 
     if (forFlexLayout) {
       return isFlex ? this : parent;
@@ -472,9 +476,9 @@ class RemoteDiagnosticsNode extends DiagnosticableTree {
     return this;
   }
 
-  // TODO(https://github.com/flutter/devtools/issues/8238): Actually determine
-  // whether this node has a box layout.
-  bool get isBoxLayout => true;
+  // Warning: This should only be used on a layout explorer node. A regular
+  // remote diagnostics node never has a "size" property.
+  bool get isBoxLayout => size != null;
 
   bool get isFlexLayout => isFlex || (parent?.isFlex ?? false);