### 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

‮
assignment->operation = AssignmentNode::OP_DIVISION;
			assignment->variant_op = Variant::OP_DIVIDE;
			break;
		case GDScriptTokenizer::Token::PERCENT_EQUAL:
			assignment->operation = AssignmentNode::OP_MODULO;
			assignment->variant_op = Variant::OP_MODULE;
			break;
		case GDScriptTokenizer::Token::LESS_LESS_EQUAL:
			assignment->operation = AssignmentNode::OP_BIT_SHIFT_LEFT;
			assignment->variant_op = Variant::OP_SHIFT_LEFT;
			break;
		case GDScriptTokenizer::Token::GREATER_GREATER_EQUAL:
			assignment->operation = AssignmentNode::OP_BIT_SHIFT_RIGHT;
			assignment->variant_op = Variant::OP_SHIFT_RIGHT;
			break;
		case GDScriptTokenizer::Token::AMPERSAND_EQUAL:
			assignment->operation = AssignmentNode::OP_BIT_AND;
			assignment->variant_op = Variant::OP_BIT_AND;
			break;
		case GDScriptTokenizer::Token::PIPE_EQUAL:
			assignment->operation = AssignmentNode::OP_BIT_OR;
			assignment->variant_op = Variant::OP_BIT_OR;
			break;
		case GDScriptTokenizer::Token::CARET_EQUAL:
			assignment->operation = AssignmentNode::OP_BIT_XOR;
			assignment->variant_op = Variant::OP_BIT_XOR;
			break;
		default:
			break; 
	}