WiFi Direct on Roku Remote seems to cause WiFi Interference on 2.4GHz. I have a Roku 3 at home and can confirm this. Unplug the Roku from power and WiFi interference is gone.
Here are my recommendations:
1) Roku needs to be hardwired
2) Customer needs WiFi AP that supports 5GHz
3) Once Roku is hardwired the WiFi Direct Roku remote should go to a channel on the 5GHz network and stop causing interference on 2.4GHz.
Other reports on online forums also suggest these steps.