Maybe you can change it at system Tools page

What's your firmware verision? As I know Archer C7(EU)_V4_170901 added AP mode. More information about this http://www.tp-link.com/en/download/Archer-C7_V4.html#Firmware

As I know in Advanced/Network/IPTV you can change the settings of IGMP. If can not, you would better contact tplink via mail.

I also face this issue, but tplink technical support tell me that there will be a firmware to resolve this issue asap. And there is a temp solution for this : When you use PPPoE dial-up, please...

Maybe the tplink technical support can help you about this issue.

Maybe you need contact tplink technical support via mail. And send them the system log for the further troubleshooting.