Hi @Anonymous User
Have you more than one television in the home to test the NOW Stick on with regards to wifi performance ?
Have you tried going into your Router settings and change the wifi channel ?
If your Router is dual band, then try both 2.4ghz and 5ghz with the Stick.
Should you have a short fly lead HDMI extender cable (like you get with a Amazon Fire Stick) then try that with the NOW Stick.
Should you be drawing power for the Stick on a USB port on your television, then try the supplied power adapter that was supplied with the Stick.