### 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

‮
} else if (op_type.type_source == GDScriptParser::DataType::UNDETECTED && !assigned_is_variant) {
			
			downgrades_assignee = !assignee_is_hard;
			downgrades_assigned = !assigned_is_hard;
		}
	}
	p_assignment->set_datatype(op_type);
	if (assignee_is_variant) {
		if (!assignee_is_hard) {
			
			mark_node_unsafe(p_assignment);
		}
	} else {
		if (assignee_is_hard && !assigned_is_hard) {
			
			mark_node_unsafe(p_assignment);
			p_assignment->use_conversion_assign = true;
			downgrades_assigned = downgrades_assigned || (!assigned_is_variant && !is_type_compatible(assignee_type, op_type, true, p_assignment->assigned_value));
		} else if (compatible) {
			if (op_type.is_variant()) {
				
				mark_node_unsafe(p_assignment);
				if (assignee_is_hard) {
					
					p_assignment->use_conversion_assign = true;
				} else {
					
					downgrades_assignee = true;
				}
			} else if (!is_type_compatible(assignee_type, op_type, assignee_is_hard, p_assignment->assigned_value)) {