I recently purchased a few Roku Expresses when I switched from Uverse to Xfinity for cable and internet so I could avoid the cable box rental fees. So far I'm able to use most of them with no problem, but I have one finicky Express that constantly drops the internet connection.
When I run the wireless check, the wifi connection is always excellent, it just says that there is no internet connection. I've unplugged/plugged in everything at least a few times, looked for firmware updates, etc. and haven't had any luck. Does anyone have any suggestions, or did I just get a bad Express?
Sometimes with WiFi just moving the device a few inches can make a marked difference in connection. In particular, try moving it a little further away from the TV, and maybe higher or lower from its current position. At 2.4 GHz, the radio wavelength is quite small (we're talking under 5 inches), so placement can really change things.
Have you also rebooted your wireless router by unplugging it from power for a minute, then trying to connect again?
I would recommend contacting your ISP to ensure that your wireless router is broadcasting a 2.4GHz Wi-Fi network, and ask for assistance in changing the wireless broadcast channel on your router. This may help eliminate wireless interference and improve your device's ability to connect. See more here: https://support.roku.com/article/213122277-tips-for-improving-the-wireless-connection-to-your-roku-s...
Please keep us posted!