Apple TV or iPhone/iPad.
If you have been using the DNS mask for any length of time, more than likely you have had some type of error or loading issue. Below are the most popular problems that I come across or have been asked about on twitter (I do make an effort to respond to each cry for help).
Here are a few things you should know right off the top. Changing your DNS setting to gain access to the American content is a loophole in the system. Netflix has not authorized this to be a working function and therefore it will be prone to errors, glitches, and slow loading. That being the case, here are a few things you can do to keep your content alive.
Unfortunately this is the price you pay for being "out of region." Because your device's physical location is being masked, there is additional signal routing that can affect loading times. In my experience, a very slow load time only happens occasionally and with continuous watching the loading improves. Patience.
There are times where the load will take forever. This should result in an error message of some kind. If you receive a "Please try again later" message, simply try again, and then again if need be. It may be that the episode is being temperamental. If after several attempts the same message continues to appear, move on to the next episode or a different series to get a successful load. If successful, go back to what you originally were wanting to watch.
If you are receiving a connection error, keep reading.
If you are able to see the content cover photos in the Netflix app but unable to stream, try restarting your Apple TV. You can find this under Settings>General>Restart (be sure you do not select reset).
If the app refuses to load, you will need to re-establish the DNS mask. This is as simple as the original set up. In the Wi-Fi settings set the DNS configuration back to "automatic" and restart the Apple TV. Open the Netflix app to ensure proper function (with your region's content). Now simply follow the original instructions again. Presto!
iPhone / iPad
Typically with mobile devices the connection needs to be re-established. For this go to Settings>Wi-Fi>YourNetworkName>Forget Network. You will then need to re-log on to your Wi-Fi. This will set the DNS back to it's standard configuration. Be sure that Netflix is closed in multi-tasking and follow the original instructions again.
I have noticed a pattern that connections and load times become patchy during the beginning of the each month. If you are having trouble during this time try the steps above or switch back to your region's content for a week or so, there might be something new you actually want to watch, lol. If you are still having trouble getting connected, this post has additional codes.
If you do have further questions, I am on Twitter and as stated above respond as best I can.