### 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 (assignee_type.has_container_element_type() && p_assignment->assigned_value->type == GDScriptParser::Node::ARRAY) {
		update_array_literal_element_type(assignee_type, static_cast<GDScriptParser::ArrayNode *>(p_assignment->assigned_value));
	}
	if (p_assignment->operation == GDScriptParser::AssignmentNode::OP_NONE && assignee_type.is_hard_type() && p_assignment->assigned_value->is_constant) {
		update_const_expression_builtin_type(p_assignment->assigned_value, assignee_type, "assign");
	}
	GDScriptParser::DataType assigned_value_type = p_assignment->assigned_value->get_datatype();
	bool assignee_is_variant = assignee_type.is_variant();
	bool assignee_is_hard = assignee_type.is_hard_type();
	bool assigned_is_variant = assigned_value_type.is_variant();
	bool assigned_is_hard = assigned_value_type.is_hard_type();
	bool compatible = true;
	bool downgrades_assignee = false;
	bool downgrades_assigned = false;
	GDScriptParser::DataType op_type = assigned_value_type;
	if (p_assignment->operation != GDScriptParser::AssignmentNode::OP_NONE && !op_type.is_variant()) {
		op_type = get_operation_type(p_assignment->variant_op, assignee_type, assigned_value_type, compatible, p_assignment->assigned_value);
		if (assignee_is_variant) {
			
			mark_node_unsafe(p_assignment);
		} else if (!compatible) {
			
			mark_node_unsafe(p_assignment);
			if (assigned_is_variant) {
				
				p_assignment->use_conversion_assign = true;
			} else {
				
				push_error(vformat(R"(Invalid operands "%s" and "%s" for assignment operator.)", assignee_type.to_string(), assigned_value_type.to_string()), p_assignment);
			}