EVENT_AFTER_SAVE_ELEMENT triggered twice after saving an entry
You can find out what the stack trace is (who is calling you) by putting something like this in your anonymous function:

                try {
                    throw new \Exception();
                } catch (\Exception $e) {
                    Craft::debug(
                        'EVENT_AFTER_SAVE_ELEMENT '.$e-&gt;getTraceAsString(),
                        __METHOD__
                    );
                }


Then search on EVENT_AFTER_SAVE_ELEMENT in your web.log