### 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

‮
switch (err.error) {
					case Callable::CallError::CALL_ERROR_INVALID_ARGUMENT: {
						PropertyInfo wrong_arg = function_info.arguments[err.argument];
						push_error(vformat(R"*(Invalid argument for "%s()" function: argument %d should be "%s" but is "%s".)*", function_name, err.argument + 1,
										   type_from_property(wrong_arg, true).to_string(), p_call->arguments[err.argument]->get_datatype().to_string()),
								p_call->arguments[err.argument]);
					} break;
					case Callable::CallError::CALL_ERROR_INVALID_METHOD:
						push_error(vformat(R"(Invalid call for function "%s".)", function_name), p_call);
						break;
					case Callable::CallError::CALL_ERROR_TOO_MANY_ARGUMENTS:
						push_error(vformat(R"*(Too many arguments for "%s()" call. Expected at most %d but received %d.)*", function_name, err.expected, p_call->arguments.size()), p_call);
						break;
					case Callable::CallError::CALL_ERROR_TOO_FEW_ARGUMENTS:
						push_error(vformat(R"*(Too few arguments for "%s()" call. Expected at least %d but received %d.)*", function_name, err.expected, p_call->arguments.size()), p_call);
						break;
					case Callable::CallError::CALL_ERROR_METHOD_NOT_CONST:
					case Callable::CallError::CALL_ERROR_INSTANCE_IS_NULL:
						break; 
					case Callable::CallError::CALL_OK:
						p_call->is_constant = true;
						p_call->reduced_value = value;
						break;
				}
			} else {
				validate_call_arg(function_info, p_call);
			}
			p_call->set_datatype(type_from_property(function_info.return_val));
			return;
		} else if (Variant::has_utility_function(function_name)) {