xzeeno wrote Hi Diamond Archer D9 ( Firmware Version:0.9.1 0.1 v0041.0 Build 150514 Rel.54055n) latest fw Changed ISP recently and still was having same issues, highly doubt a WAN would be affecting...

Upgrade the latest firmware (TD-W8980_V1_150514) first. http://www.tp-link.com/en/download/TD-W8980_V1.html#Firmware After upgrade, reset and reconfigure it. If the problem continues, you can try...

With WN823N installed, you can detect the Wi-Fi network but fail to connect? Any error message? You'd better describe the problem in details.

improve streaming content? Do you mean improve the speed?

Have you tried to reset them to factory defaults via utility? http://www.tp-link.com/en/download/TL-PA6030KIT_V1.html#Utility http://www.tp-link.com/en/faq-312.html After reset, if still no powerline...

@bigdog989 Firmware of your D7 is up to date? Provide the topology. Besides, does it also happen on wired clients or other wireless clients except the apple device? @xzeeno Your model is D7 or D9?...