### Godot version

4.0.beta10.mono.official

### System information

Windows 11

### Issue description

After registering a C# Script with Autoload and trying to connect to a signal using the `Signal.connect` method (`Singleton.Signal.connect(xxx)`) fails with `Invalid get index 'Signal' (on base: 'Node (Singleton.cs)'). But with `Object.connect` it works.

### Steps to reproduce

- Create a C# class script with a Signal named `Signal` (could be any other).
- Register it with Autoload with the name `Singleton` (could be any other).
- Create a GDScript script and try to connect the Singleton's signal using `Singleton.Signal.connect(xxx)`
- When running the project it fails with `Invalid get index 'Sample' (on base: 'Node (Singleton.cs)').`

### Minimal reproduction project

[example.zip](https://github.com/godotengine/godot/files/10414500/example.zip)

r_iarg.def_param_value = p_val;
	r_iarg.default_argument = p_val.operator String();
	switch (p_val.get_type()) {
		case Variant::NIL:
			
			r_iarg.default_argument = "default";
			break;
		
		case Variant::BOOL:
			r_iarg.default_argument = bool(p_val) ? "true" : "false";
			break;
		case Variant::INT:
			if (r_iarg.type.cname != name_cache.type_int) {
				r_iarg.default_argument = "(%s)" + r_iarg.default_argument;
			}
			break;
		case Variant::FLOAT:
			if (r_iarg.type.cname == name_cache.type_float) {
				r_iarg.default_argument += "f";
			}
			break;
		case Variant::STRING:
		case Variant::STRING_NAME:
		case Variant::NODE_PATH:
			if (r_iarg.type.cname == name_cache.type_StringName || r_iarg.type.cname == name_cache.type_NodePath) {
				if (r_iarg.default_argument.length() > 0) {
					r_iarg.default_argument = "(%s)\"" + r_iarg.default_argument + "\"";
					r_iarg.def_param_mode = ArgumentInterface::NULLABLE_REF;