### 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 (!p_can_assign) {
		push_error("Assignment is not allowed inside an expression.");
		return parse_expression(false); 
	}
	if (p_previous_operand == nullptr) {
		return parse_expression(false); 
	}
#ifdef DEBUG_ENABLED
	VariableNode *source_variable = nullptr;
#endif
	switch (p_previous_operand->type) {
		case Node::IDENTIFIER: {
#ifdef DEBUG_ENABLED