Repeater and EditAction error

foreach() argument must be of type array|object, string given {"userId":1,"exception":"[object] (ErrorException(code: 0): foreach() argument must be of type array|object, string given at /var/www/html/vendor/filament/forms/src/Components/Repeater.php:783)

Below is how I try to 

->beforeFormFilled(function (EditAction $action, Order $record) {
                            // Runs before the form fields are populated from the database.
                            // dd(gettype(json_decode($record['items'],true)));
                            $record['items'] = json_decode($record['items'], true);
                        })
 dd(gettype(json_decode($record['items'])));
                            $record['items'] = json_decode($record['items'], true);