### 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
return active;
		}
		void set_active(bool p_active) {
			toggle_button->set_pressed(p_active);
			active = p_active;
		}
		LogFilter(MessageType p_type) :
				type(p_type) {
		}
	};
	Vector<LogMessage> messages;
	
	HashMap<MessageType, LogFilter *> type_filter_map;
	RichTextLabel *log = nullptr;
	Button *clear_button = nullptr;
	Button *copy_button = nullptr;
	Button *collapse_button = nullptr;
	bool collapse = false;
	Button *show_search_button = nullptr;
	LineEdit *search_box = nullptr;
	
	
	Button *tool_button = nullptr;
	bool is_loading_state = false; 
	Timer *save_state_timer = nullptr;
	static void _error_handler(void *p_self, const char *p_func, const char *p_file, int p_line, const char *p_error, const char *p_errorexp, bool p_editor_notify, ErrorHandlerType p_type);
	ErrorHandlerList eh;
	Thread::ID current;