Craft error when attempting to edit an entry with emoji

[olets]

Craft supports some emoji

If add an allowed emoji to an entry (e.g. 👍 in the source view of a Redactor field, to render 👍), save the entry, and then try to edit the entry, I get

Array
(
[code] => 400
[message] => HTTP/1.1 400 Bad Request
[response] => stdClass Object
(
[errors] => Array
(
[0] => stdClass Object
(
[code] => NOT_ALLOWED
)

)

)

)
in </path/to>/craft/plugins/applenews/vendor/chapter-three/apple-news-api/src/PublisherAPI/Base.php on line 197

</path/to>/craft/plugins/applenews/vendor/chapter-three/apple-news-api/src/PublisherAPI/Base.php(289)

277   /**
278    * Error handler.
279    *
280    * @param (string) $message Error message to display.
281    * @param (const) $message_type Predefined Constants
282    *
283    * @see http://php.net/manual/en/errorfunc.constants.php
284    */
285   public function triggerError($message, $message_type = E_USER_NOTICE) {
286     $debug_backtrace = debug_backtrace();
287     $trace = $debug_backtrace[0];
288     trigger_error($message . ' in ' . $trace['file'] . ' on line ' .
289       $trace['line'], $message_type);
290   }
291 
292 }

Guessing this is a plugin bug, sending an unexpected character to chapter-three's apple-new-api?