"Chat" not working with 4.7 RC

currently with 4.7 RC "Chat" does not show any text in a group chat (buddypress) if "plugin AJAX" is used.
it seems to work perfectly if "wordpress AJAX" is used.
i had a similar problem previously with using the "plugin AJAX" together with "Defender" ;
https://premium.wpmudev.org/forums/topic/make-allowance-for-chat-plugin-with-prevent-php-execution
but that was sorted out using code in .htaccess in wp-content folder.
not sure if it may be related, just thought i would mention it.
the plugin clearly states that ;
"The WordPress AJAX will be much slower and user more server resources than using the Plugin AJAX."
so i thought i would bring this to attention in case it has to do with upcoming wordpress 4.7
"Support Access" Granted if needed.
any kind support and assistance in this would be greatly appreciated.
kind regards,
RC.