Q: latest ATV just buffers constantly we have ultra fast fibre what is its problem?

That indicates a network issue, another device working won't rule that out

What is the current connection via speedtest?

Mmake sure DNS is set to auto (settings - general - network)

If on wifi try Ethernet

To see a current status of the network get a report from istumbler, or similar. Look for signal strength, noise, nearby networks

Test on another network

I've started having the same issue with buffering video around December with Netflix, Youtube, HBO Now, and The Weather Channel. Running SpeedTest on my ATV4 I get around 19-22mbps, still my video buffers or quality of the video drops. I would go to the Netflix app on my SmartTV and no issues with streaming. I have taken the ethernet from my TV to place in the Apple TV and no change. I just recently restored my Apple TV back to the factory settings, still didn't help.

Wondering if I have a faulty device?

Make sure DNS is set to auto (settings - general - network)

Make sure router is up to date

Reboot ATV and router

Ttry a reinstall of Netflix app

Test on another network

Same issue here,my library takes forever to load like half an hour for an episode of game of thrones,ridiculous!!!!!also when it gets to play there is a lot of buffering throughout the episode,also experienced buffering with the FX Now app,it doesn't happen with rentals though it seems to be a problem with my library,tried restarting but nothing....my wifi is super fast at 50mbps and my laptop and iPhone are perfectly working,i have 2 Apple TV 3 and they work flawless if Apple doesn't send an update or fix the issue somehow I'm filling for a refund.

There is nothing for Apple to fix as it is a network issue on your end. Other devices working isn't going to rule that out

Was the current connection verified? DNS? Diagnostic report? Ethernet?

Sure are a lot of people with network issues.  I always wondered why there were so many "refurbished" Apple TV's available.When just about every media box can play back everything thrown at it and then the Apple just chokes on it----I can see why people get frustrated.

Apple needs to retool their streaming feeds to people who have this kind of "network" issue to whatever the other media devices use that don't seem to have this issue.  I know you will not understand my logic but come on....I have 3 other media boxes...western digital, roku, and asus player that loves my network the way it is....BUT Apple just buffers on the same content that the others run without a problem.

So....that's why you will continue to see people asking for help concerning buffering in the future.  Glad you guys can just copy and paste the same "help" info.

Sure is a network connection on my end...you keep saying that to anyone reporting this type of issue,if my laptop,iPad,iPhone,PS4 and 2 ATV3 are working fine how it is a network issue on my end?,also takes like 20 minutes to load an episode of game of thrones from my library when the ATV3 plays it in 3 seconds,so is it a stil a network issue on my end?,i thank you for taking the time to reply but please stop saying everyone with this issue the same thing when is clearly an apple issue with the ATV4's software,so if you are not going to add something helpful to resolve the issue better don't reply,thanks.

There are a select group that post issues, it is working just fine for the majority. Just because other devices are working, that in no way rules out a network issue. No, if there is something on ones network that is causing the issue then it is their responsibility to do proper troubleshooting. If you took the device to another network you would also see that it works just fine. But yet, you just want to make an assumption and point the finger.

DNS is set to automatic, everything up to date on my gateway, reinstalled everything on the ATV4, haven't tried another network.

Everything was working fine until December. Hooked up my ATV3 and it worked like a champ. Thinking a recent software update may have changed things.

Unlikely to be software related. I would test it on another network or take it to Apple for testing.