Fix MenuButton style in editor top menu bar

editor/plugins/mesh_instance_3d_editor_plugin.cpp

@@ -569,6 +569,8 @@ MeshInstance3DEditor::MeshInstance3DEditor() {
 	options = memnew(MenuButton);
 	options->set_text(TTR("Mesh"));
 	options->set_switch_on_hover(true);
+	options->set_flat(false);
+	options->set_theme_type_variation("FlatMenuButton");
 	Node3DEditor::get_singleton()->add_control_to_menu_panel(options);
 
 	options->get_popup()->add_item(TTR("Create Collision Shape..."), MENU_OPTION_CREATE_COLLISION_SHAPE);

editor/plugins/mesh_library_editor_plugin.cpp

@@ -278,6 +278,8 @@ MeshLibraryEditor::MeshLibraryEditor() {
 	menu->set_position(Point2(1, 1));
 	menu->set_text(TTR("MeshLibrary"));
 	menu->set_button_icon(EditorNode::get_singleton()->get_editor_theme()->get_icon(SNAME("MeshLibrary"), EditorStringName(EditorIcons)));
+	menu->set_flat(false);
+	menu->set_theme_type_variation("FlatMenuButton");
 	menu->get_popup()->add_item(TTR("Add Item"), MENU_OPTION_ADD_ITEM);
 	menu->get_popup()->add_item(TTR("Remove Selected Item"), MENU_OPTION_REMOVE_ITEM);
 	menu->get_popup()->add_separator();

editor/plugins/multimesh_editor_plugin.cpp

@@ -273,6 +273,8 @@ MultiMeshEditor::MultiMeshEditor() {
 
 	options->set_text("MultiMesh");
 	options->set_button_icon(EditorNode::get_singleton()->get_editor_theme()->get_icon(SNAME("MultiMeshInstance3D"), EditorStringName(EditorIcons)));
+	options->set_flat(false);
+	options->set_theme_type_variation("FlatMenuButton");
 
 	options->get_popup()->add_item(TTR("Populate Surface"));
 	options->get_popup()->connect(SceneStringName(id_pressed), callable_mp(this, &MultiMeshEditor::_menu_option));

editor/plugins/parallax_background_editor_plugin.cpp

@@ -133,5 +133,7 @@ ParallaxBackgroundEditorPlugin::ParallaxBackgroundEditorPlugin() {
 	menu->get_popup()->add_item(TTR("Convert to Parallax2D"), MENU_CONVERT_TO_PARALLAX_2D);
 	menu->set_text(TTR("ParallaxBackground"));
 	menu->set_switch_on_hover(true);
+	menu->set_flat(false);
+	menu->set_theme_type_variation("FlatMenuButton");
 	toolbar->add_child(menu);
 }

editor/plugins/particles_editor_plugin.cpp

@@ -118,6 +118,8 @@ ParticlesEditorPlugin::ParticlesEditorPlugin() {
 
 	menu = memnew(MenuButton);
 	menu->set_switch_on_hover(true);
+	menu->set_flat(false);
+	menu->set_theme_type_variation("FlatMenuButton");
 	toolbar->add_child(menu);
 	menu->get_popup()->connect(SceneStringName(id_pressed), callable_mp(this, &ParticlesEditorPlugin::_menu_callback));
 }

editor/plugins/skeleton_2d_editor_plugin.cpp

@@ -96,6 +96,8 @@ Skeleton2DEditor::Skeleton2DEditor() {
 
 	options->set_text(TTR("Skeleton2D"));
 	options->set_button_icon(EditorNode::get_singleton()->get_editor_theme()->get_icon(SNAME("Skeleton2D"), EditorStringName(EditorIcons)));
+	options->set_flat(false);
+	options->set_theme_type_variation("FlatMenuButton");
 
 	options->get_popup()->add_item(TTR("Reset to Rest Pose"), MENU_OPTION_SET_REST);
 	options->get_popup()->add_separator();

editor/plugins/sprite_2d_editor_plugin.cpp

@@ -586,6 +586,8 @@ Sprite2DEditor::Sprite2DEditor() {
 	CanvasItemEditor::get_singleton()->add_control_to_menu_panel(options);
 
 	options->set_text(TTR("Sprite2D"));
+	options->set_flat(false);
+	options->set_theme_type_variation("FlatMenuButton");
 
 	options->get_popup()->add_item(TTR("Convert to MeshInstance2D"), MENU_OPTION_CONVERT_TO_MESH_2D);
 	options->get_popup()->add_item(TTR("Convert to Polygon2D"), MENU_OPTION_CONVERT_TO_POLYGON_2D);

modules/csg/editor/csg_gizmos.cpp

@@ -156,6 +156,8 @@ CSGShapeEditor::CSGShapeEditor() {
 	options->hide();
 	options->set_text(TTR("CSG"));
 	options->set_switch_on_hover(true);
+	options->set_flat(false);
+	options->set_theme_type_variation("FlatMenuButton");
 	Node3DEditor::get_singleton()->add_control_to_menu_panel(options);
 
 	options->get_popup()->add_item(TTR("Bake Mesh Instance"), MENU_OPTION_BAKE_MESH_INSTANCE);