### Godot version

master ([06ccbfe](https://github.com/godotengine/godot/commit/06ccbfe8eec6e840db3df2360dc2804386f940b8))

### System information

PopOS 22.04

### Issue description

Sometimes the doc page is broken when the engine is closed and then restarted.
Closing the doc and opening it again fixes it.

![2023-05-27_22-15](https://github.com/godotengine/godot/assets/3624853/ed202a55-03e8-420a-bc1c-ccfc7f7cd02a)


### Steps to reproduce

- Open a documentation page for any node
- Restart Godot

### Minimal reproduction project

NA

EDIT : Added the commit hash @Calinou 
MENU_COPY,
		MENU_SELECT_ALL,
		MENU_MAX
	};
	enum DefaultFont {
		NORMAL_FONT,
		BOLD_FONT,
		ITALICS_FONT,
		BOLD_ITALICS_FONT,
		MONO_FONT,
		CUSTOM_FONT,
	};
protected:
	virtual void _update_theme_item_cache() override;
	void _notification(int p_what);
	static void _bind_methods();
private:
	struct Item;
	struct Line {
		Item *from = nullptr;
		Ref<TextParagraph> text_buf;
		Color dc_color;
		int dc_ol_size = 0;
		Color dc_ol_color;
		Vector2 offset;
		int char_offset = 0;
		int char_count = 0;
		Line() { text_buf.instantiate(); }