### Godot version

3b086aa06

### System information

ArchLinux x11

### Issue description

```gdscript
extends Node

@export_group("My Properties")
@export var number = 3
@export var string = ""

@export_group("Prefixed Properties", "prefix_")
@export var prefix_number = 3
@export var prefix_string = ""

@export_group("", "")
@export var ungrouped_number = 3
```

![image](https://user-images.githubusercontent.com/70787919/214983963-528c415b-745b-47fc-9777-36ebe31a3060.png)


### Steps to reproduce

- create script
- @export_group
- go inspector

### Minimal reproduction project

‮
if (declared_return.kind != GDScriptParser::DataType::BUILTIN || declared_return.builtin_type != Variant::NIL) {
				push_error("Constructor cannot have an explicit return type.", p_function->return_type);
			}
		}
	} else {
		if (p_function->return_type != nullptr) {
			p_function->set_datatype(type_from_metatype(resolve_datatype(p_function->return_type)));
		} else {
			
			
			GDScriptParser::DataType return_type;
			return_type.type_source = GDScriptParser::DataType::INFERRED;
			return_type.kind = GDScriptParser::DataType::VARIANT;
			p_function->set_datatype(return_type);
		}
#ifdef TOOLS_ENABLED
		
		
		GDScriptParser::DataType base_type = parser->current_class->base_type;
		GDScriptParser::DataType parent_return_type;
		List<GDScriptParser::DataType> parameters_types;
		int default_par_count = 0;
		bool is_static = false;
		bool is_vararg = false;
		if (!p_is_lambda && get_function_signature(p_function, false, base_type, function_name, parent_return_type, parameters_types, default_par_count, is_static, is_vararg)) {
			bool valid = p_function->is_static == is_static;
			valid = valid && parent_return_type == p_function->get_datatype();
			int par_count_diff = p_function->parameters.size() - parameters_types.size();
			valid = valid && par_count_diff >= 0;
			valid = valid && default_value_count >= default_par_count + par_count_diff;