### 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

‮
#include "gdscript_analyzer.h"
#include "core/config/engine.h"
#include "core/config/project_settings.h"
#include "core/core_string_names.h"
#include "core/io/file_access.h"
#include "core/io/resource_loader.h"
#include "core/object/class_db.h"
#include "core/object/script_language.h"
#include "core/templates/hash_map.h"
#include "gdscript.h"
#include "gdscript_utility_functions.h"
#include "scene/resources/packed_scene.h"
#define UNNAMED_ENUM "<anonymous enum>"
#define ENUM_SEPARATOR "::"
static MethodInfo info_from_utility_func(const StringName &p_function) {