Did you try to reset YouView box? All channels or some channels cannot be received?

What's the SNR Margin on Status page of your VR900? I'm afraid that we cannot modify it manually. Did you try to contact your ISP or test by a different modem?

Maybe the following guide is helpful. http://www.tp-link.com/en/faq-537.html

WLAN light should be flashing... Sounds like faulty... Reset the router to factory defaults by pressing the reset button for about 10 seconds. if it is the same, it should be faulty. Try to get a...

Your ISP doesn't provide IPv6 service and there is no IPv6 IP address on web interface of D5? Update your andorid devices to latest version.

Well, there is no newer firmware than the current version of your D2... Reset it to factory defaults and have a check again. If it is the same, you may submit a ticket here....