### 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

‮
GDScriptTokenizer::Token::Type op_type = previous.type;
	LiteralNode *constant = alloc_node<LiteralNode>();
	complete_extents(constant);
	switch (op_type) {
		case GDScriptTokenizer::Token::CONST_PI:
			constant->value = Math_PI;
			break;
		case GDScriptTokenizer::Token::CONST_TAU:
			constant->value = Math_TAU;
			break;
		case GDScriptTokenizer::Token::CONST_INF:
			constant->value = INFINITY;
			break;
		case GDScriptTokenizer::Token::CONST_NAN:
			constant->value = NAN;
			break;
		default:
			return nullptr; 
	}
	return constant;
}
GDScriptParser::ExpressionNode *GDScriptParser::parse_unary_operator(ExpressionNode *p_previous_operand, bool p_can_assign) {