### Godot version

4.0.stable

### System information

Windows 10

### Issue description

In my project, we are rendering a GUI to a QuadMesh as an in-game interactive display. We push mouse click events when the player clicks the display. This worked fine during 4.0 beta, but after moving to the stable release the buttons on TreeItems stopped working. I put together a MRP and went back through the versions and it seems the issue started in RC1.

### Steps to reproduce

When running the MRP, it has a standard GUI on the left hand side of the screen and a QuadMesh rendered GUI on the right hand side. If you click the + button on an item, it will add another item to the list. On the QuadMesh you will see that you can highlight and collapse items in the list, but the + button does not function. If you run the MRP on 4.0.beta17 everything will function as expected.

### Minimal reproduction project

[TreeUI_through_SubViewport.zip](https://github.com/godotengine/godot/files/10959159/TreeUI_through_SubViewport.zip)

void set_theme_owner_node(Node *p_node);
	Node *get_theme_owner_node() const;
	bool has_theme_owner_node() const;
	void set_theme(const Ref<Theme> &p_theme);
	Ref<Theme> get_theme() const;
	void set_theme_type_variation(const StringName &p_theme_type);
	StringName get_theme_type_variation() const;
	void begin_bulk_theme_override();
	void end_bulk_theme_override();
	void add_theme_icon_override(const StringName &p_name, const Ref<Texture2D> &p_icon);
	void add_theme_style_override(const StringName &p_name, const Ref<StyleBox> &p_style);
	void add_theme_font_override(const StringName &p_name, const Ref<Font> &p_font);
	void add_theme_font_size_override(const StringName &p_name, int p_font_size);
	void add_theme_color_override(const StringName &p_name, const Color &p_color);
	void add_theme_constant_override(const StringName &p_name, int p_constant);
	void remove_theme_icon_override(const StringName &p_name);
	void remove_theme_style_override(const StringName &p_name);
	void remove_theme_font_override(const StringName &p_name);
	void remove_theme_font_size_override(const StringName &p_name);
	void remove_theme_color_override(const StringName &p_name);
	void remove_theme_constant_override(const StringName &p_name);
	Ref<Texture2D> get_theme_icon(const StringName &p_name, const StringName &p_theme_type = StringName()) const;
	Ref<StyleBox> get_theme_stylebox(const StringName &p_name, const StringName &p_theme_type = StringName()) const;
	Ref<Font> get_theme_font(const StringName &p_name, const StringName &p_theme_type = StringName()) const;
	int get_theme_font_size(const StringName &p_name, const StringName &p_theme_type = StringName()) const;
	Color get_theme_color(const StringName &p_name, const StringName &p_theme_type = StringName()) const;
	int get_theme_constant(const StringName &p_name, const StringName &p_theme_type = StringName()) const;
	bool has_theme_icon_override(const StringName &p_name) const;
	bool has_theme_stylebox_override(const StringName &p_name) const;