### Godot version

4.2.dev1

### System information

Manjaro Linux (DE: Cinnamon v5.8.4) 64 bits

### Issue description

The title already explains it. Take a look at the steps to reproduce below.

### Steps to reproduce

In a GDScript `_ready()` function write this:
```print_rich("[color=red]Red line\n2nd red line[/color]")```

the second line is not red and the output is as follow:
![Capture d’écran du 2023-07-29 05-50-16](https://github.com/godotengine/godot/assets/102065761/554038c6-d128-40c9-8c88-237b44b35b12)

I tested all the the possible BBCodes for the print_rich() method (as stated in the documentation), and of course they all failed.

The RichTextLabel in my projects works as expected.

### Minimal reproduction project

N/A
LogMessage(const String p_text, MessageType p_type) :
				text(p_text),
				type(p_type) {
		}
	};
	struct {
		Color error_color;
		Ref<Texture2D> error_icon;
		Color warning_color;
		Ref<Texture2D> warning_icon;
		Color message_color;
	} theme_cache;
	
	struct LogFilter {
	private:
		
		int message_count = 0;
		bool active = true;
	public:
		MessageType type;
		Button *toggle_button = nullptr;
		void initialize_button(const String &p_tooltip, Callable p_toggled_callback) {