### 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

‮
push_text("Class ");
	if (p_class->identifier == nullptr) {
		push_text("<unnamed>");
	} else {
		print_identifier(p_class->identifier);
	}
	if (p_class->extends_used) {
		bool first = true;
		push_text(" Extends ");
		if (!p_class->extends_path.is_empty()) {
			push_text(vformat(R"("%s")", p_class->extends_path));
			first = false;
		}
		for (int i = 0; i < p_class->extends.size(); i++) {
			if (!first) {
				push_text(".");
			} else {
				first = false;
			}
			push_text(p_class->extends[i]);
		}
	}
	push_line(" :");
	increase_indent();
	for (int i = 0; i < p_class->members.size(); i++) {
		const ClassNode::Member &m = p_class->members[i];
		switch (m.type) {