Same problem here. But for me, simply exiting the Netflix app everytime did not work to stop the issue of non-responsiveness from happening again. However, I've found that if you log out of your Netflix account after each use, you shouldn't run into any problems. While it is a minor annoynace to have to log out each time and then put in your password everytime you want to watch something, it is much less of an annoyance than having to unplug the TV or having to do a Smarthub reset and then resigning into your samsung account and then your netflix account.
This has been working for me for a week now with no problems.... This solution stopped me from returning the TV tpo Bestbuy although I would appreciate a more official solution from Samsung/Netflix
What seems to be working for me is:
Once I've gotten into Netflix, by unplugging or any other means, and Netflix is running OK:
1. I get out of Netflix by getting to the screen that has an option "Exit Netflix" and I use that option.
2. This brings up the Smarthub banner with all the apps across the bottom of the screen
3. I wait until this banner has completely disappeared before proceeding to any other option.
If I want to go from Netrflix to Amazon, I exit Netflix, wait until the banner disappears, hit the Smarthub button on the remote, choose Amazon, and all's ok. If I try to go from Netflix to banner and then immediately go to Amazon or HDMI, it works, but seems to mess up Netflix again so that I've got to unplug-replug the set again.