You can contact support.fr@tp-link.com for help.

What is the version of your C9？ You may try to do firmware recovery in the way below: http://forum.tp-link.com/showthread.php?81462-How-to-recovery-the-router-when-you-bricked-it&highlight=fitz...

It is not suggested to downgrade the firmware. You can contact support@tp-link.com to ask whether they have a solution for your case.

Great news. Thank you for sharing.

Glad to hear it is working now.;)

You may contact apple support to see if they have meet the similar issue. Besides, you can modify the DNS server on the ipad or reset the ipad to factory default to have a try.