On Device Info page, what can you see? :)

The router should reconnect automatically as WAN connection type is dynamic IP. Connect the modem directly to your PC instead of WAN2. Does it disconnect and reconnect automatically?

I replied you in another thread.

The PC is running in Windows 7? Download the chipmaker's driver AR9271 for WN722NC, https://www.atheros.cz/atheros-wireless-drivers.html Try to install the driver manually....

Log in web interface of W8961ND, On Status page, in Wireless section, it shows Current Connected Wireless Clients number and there is a list of wireless clients connected. Cannot disconnect the...

Not sure. Read this article to figure it out. http://www.tp-link.com/en/article/?faqid=741