I have a Samsung UN55HU8550FX. It is 2 years old. It is connected to my home network via ethernet. I have very strong, reliable high speed internet.
I have had nothing but trouble with the Netflix app on this TV since I bought it. It works perfectly for about 2 days after it is powered on, then it begins to misbehave - starting as soon as Netflix loads, when it kicks me out and makes me reload it. On the third day, every time I watch a program and try to fast forward or rewind, it either loads audio but no video, or video but no audio. By the fourth day, every time I fast forward or rewind the screen goes black and Netflix freezes. By the fifth day nothing works at all. If I then unplug it for 5 minutes, the whole process starts over again.
I have tried every suggestion I could find on various forums and tech sites, I have had lengthy conversations with Samsung senior tech support representatives. At first Samsung blamed it on my internet connection, which was a bogus suggestion. Then they insisted I reinstall the SmartHub, which did not fix the problem. Then they insisted I upgrade the firmware, which did not fix the problem. Then they made various changes in the settings, which did not fix the problem. Then they told me to reload the Netflix app, which did not solve the problem. Then they blamed Netflix, saying this problem happens when the Netflix servers are busy. This is unlikely to be my problem, as I mostly watch TV between 11 pm and 4 am U.S. time, which is hardly peak TV viewing time.
Then they said "Just unplug it every 5 days" but I told them this was a completely unacceptable solution. I did not pay $1500 for a TV that I have to unplug every 5 days.
After these conversations with Samsung I got assertive and asked to speak to a senior engineer. I told him it was obvious that the Netflix app has problems, because 1) I have no problem with Netflix on my PC; 2) I have no problem with Netflix on my older, Sony TV in the bedroom which uses a Roku to connect to Netflix; 3) I have no problem with the Hulu app on Samsung TV; 3) I have no problem with the YouTube app on Samsung TV; and 4) I have no problem with the Acorn app on Samsung TV.
The senior engineer listened, agreed that rebooting every 5 days was an unacceptable solution, and said a more senior engineer would contact me within 24 hours. Amazingly, they actually called back the next day. The more senior engineer agreed that the Netflix app was buggy, and said they would work with Netflix to get a new one, which he thought would be available within one month (that would be January 2017). I will believe it when I see it.
If this TV was a computer I would know exactly what was wrong with it. I know very little about TVs, but I have 25 years experience with computers, so if it was a computer I would guess it had a cache problem and the cache was filling up as days go by and not being cleared out. This would explain why it works OK for 2 days, then slowly works less and less, after which unplugging it for 5 minutes works - could it be clearing the Netflix cache? I find nothing online that specifically mentions a cache.
Why only the Netflix app has this problem, and not Hulu and YouTube and Acorn, I couldn't say. Perhaps those apps are written to clear the cache upon closing? Just guessing.
At my last job we had a problem with some fax server software where the software would stop working on an end user's PC if there were more than 99 files stored in the TEMP folder. I installed software that the cleared the TEMP folder every time the users logged in, and presto chango! The fax software never misbehaved again. This is what makes me think there might be a cache problem with the Samsung Netflix app. As I said, I am not a TV expert, but it seems like a logical idea.
I have read on several of these forums that turning off "Instant On" solves the problem. Netflix Tech Support never suggested this. I have just turned it off. I will let you know in 5 days if that solves the problem.