### 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

‮
mark_node_unsafe(p_origin);
	parser->push_error(p_message, p_origin);
}
void GDScriptAnalyzer::mark_node_unsafe(const GDScriptParser::Node *p_node) {
#ifdef DEBUG_ENABLED
	if (p_node == nullptr) {
		return;
	}
	for (int i = p_node->start_line; i <= p_node->end_line; i++) {
		parser->unsafe_lines.insert(i);
	}
#endif
}
void GDScriptAnalyzer::downgrade_node_type_source(GDScriptParser::Node *p_node) {
	GDScriptParser::IdentifierNode *identifier = nullptr;
	if (p_node->type == GDScriptParser::Node::IDENTIFIER) {
		identifier = static_cast<GDScriptParser::IdentifierNode *>(p_node);
	} else if (p_node->type == GDScriptParser::Node::SUBSCRIPT) {
		GDScriptParser::SubscriptNode *subscript = static_cast<GDScriptParser::SubscriptNode *>(p_node);
		if (subscript->is_attribute) {
			identifier = subscript->attribute;
		}
	}
	if (identifier == nullptr) {
		return;
	}