Is that when you use Skype video call, all devices connected with router AC3200 can not surf the Internet and the router crashed? If that is, you would better contact support@tp-link.com for the...

Maybe tplink technical support can help you out. Please contact them via mail.

I make a mistake that C9 support WDS function. I have found at Advanced->SystemTools -> System Parameters there is able to enable WDS Bridging function. My Archer C9_V5 with the firmware 160927

It seems that C9 can not support WDS mode. You would better check it with TPLINK support

Maybe you can contact tplink support via mail or hotline.

It seems that V4 have a better wireless performance. For more information about these version, you can see http://www.tp-link.com/en/download/TL-WR802N_V4.html there are V2/V3/V4 UG at this webpage.