### Godot version

4.1 dev2, 4.0.3

### System information

Windows 10, ryzen 5900x, radeon 6950xt (driver: 23.2.2)

### Issue description

There are two bugs:
- When I create a new node, it is created outside of the viewport. (as in first video)
- When I run the project, all the content inside the viewport dont appear. (as in second video)
I believe the second issue is related to the first.

Note: these problems are in RTL editors.

https://github.com/godotengine/godot/assets/121864036/84f0d434-0d1b-4c23-9fb0-510257e2e191


https://github.com/godotengine/godot/assets/121864036/b2bc20c7-1e2e-4d04-99e7-d66860ffced2




### Steps to reproduce

Videos explain.

### Minimal reproduction project

N/A
ERR_READ_THREAD_GUARD_V(0);
	if (!data.initialized) {
		WARN_PRINT_ONCE("Attempting to access theme items too early; prefer NOTIFICATION_POSTINITIALIZE and NOTIFICATION_THEME_CHANGED");
	}
	if (p_theme_type == StringName() || p_theme_type == get_class_name() || p_theme_type == data.theme_type_variation) {
		const int *font_size = data.theme_font_size_override.getptr(p_name);
		if (font_size && (*font_size) > 0) {
			return *font_size;
		}
	}
	if (data.theme_font_size_cache.has(p_theme_type) && data.theme_font_size_cache[p_theme_type].has(p_name)) {
		return data.theme_font_size_cache[p_theme_type][p_name];
	}
	List<StringName> theme_types;
	data.theme_owner->get_theme_type_dependencies(this, p_theme_type, &theme_types);
	int font_size = data.theme_owner->get_theme_item_in_types(Theme::DATA_TYPE_FONT_SIZE, p_name, theme_types);
	data.theme_font_size_cache[p_theme_type][p_name] = font_size;
	return font_size;
}
Color Control::get_theme_color(const StringName &p_name, const StringName &p_theme_type) const {