udanwudeligv
To be honest, I'm not really sure what the problem could be. Perhaps BirdDog, or one of the other more knowledgeable people in here might have an idea of what you can try other than what I list below.
If the devices you are trying to stream on are connected by Wi-Fi, you might try, if you have the ability to do so, connecting a device directly to the modem with a LAN cable and see if it makes any difference. If you have a device with which you can directly connect, but that doesn't have the ability to stream with Netflix, you could still run some speed tests to see if you are getting the same results as Wi-Fi. If not, perhaps there is something going on with the Wi-Fi connection and this is what's causing the inability to stream.
http://testmy.net/
When you speed test, you should be running the tests under and account you create at testmy.net. Also, when you run the tests, make sure to use the 25MB test file size for download tests and the 4MB test file size for upload tests, but the download tests are the more important of the two.
This is really the only thing I can think of trying. If this doesn't tell you anything, I hope someone more knowledgeable than I can help.
P.S. I know that they are almost assuredly still fiddling with the gateways and even the entire system to get it "dialed in", if you will, but I don't know if that would have anything to do with this issue.
Edit: Posted a few seconds after BirdDog, so I didn't know he had chimed in already. I also agree that it might be best to start a new post for this issue. Make sure to start it in "Tech Support."