Hi,
I have no idea what i can do. Im not able to watch 4k movies anymore from my server.
I have done a lot of speedtest with the apple tv and ipad pro.
Ipad Speed internet: 200 Mbps
Ipad speed server: 65 Mbps
So i have no problem to watch the 4k stuff from my server on the Ipad pro
Apple TV speed Internet: 85 Mbps
Apple TV speed Server: 13 Mbps - 21 Mbps
Im not able to watch 4k movies because its buffering all the time. The Server speed test ist done through Infuse. Ipad and Apple TV are in the same Wifi (5GHz)
The Infuse settings are on both the same, SMB Auto and Port 445.
Why does the Apple TV loads the data so slow?
I really hope someone can help me. Thanks in advance.
Just as a test, could you try using an Ethernet cable on the ATV to see if the speed is higher?
The speed tests don’t always show the quality of the connection and along with low speed if it’s also a poor quality connection with errors it will not work well.
WiFi is very finicky, moving the ATV just a foot or two could change everything as well as moving nearby metal objects like picture frames etc. Don’t ask how I know this. LOL
It used to work in the past just fine.
My ATV is to far away to test it with a cable.
But I do have a very strong 5GHz signal.
The very interisting part is, that at the moment with the Apple TV i can‘t connect to the 2.4 Ghz Wifi of the Router.
I do have a 2.4 GHz repeater via cable connectet to the router. When i‘m conected to the repeater i do have
Internet speed 35 Mbps
Server speed 29-30 Mbps
It all doesn‘t make sens, it it an infuse, router or apple tv problem? 
Well, like I said, WiFi is a finicky beast. I actually had a case where what had worked flawlessly for over 2 years one day just drop 80% in speed. After over a week of trouble shooting the culprit was a metal closet rack installed in an adjacent room. Moved the affected device less than 3 feet from where it was and got back to about 90% signal and flawless function again.
5 Ghz is far more susceptible to interference and attenuation compared to the 2.4 Ghz band so there’s a trade off in speed and range between the two.
Good luck in your search! As a side note, WiFi is the exact reason I keep a 100’ Ethernet cable in my tool kit. Get a bright orange one so the family doesn’t trip on it while you test. 
You will want to have >120Mbps to be able to stream 4K reliably. Without a gigabit connection you can’t really do a internet Speedtest to tell you the connection strength. For instance , if you can get a theoretical 1000Mbps connection to your router but your internet is only 200, then the router can fail 4 out of 5 times and still maintain the 200 connection.
I personally recently had the WiFi go out in one of my routers. It still had a signal but it was no where near as strong as it should have. So without doing an Ethernet connection to your server it will be hard to track down.
I pay for a 200mbit internet connection and I do get 200 mbit on the Ipad through the 5Ghz network. So that works just fine. I dont get it through the Apple TV 4K.
I just ordered a 15 Meter Ethernet cable to do some tests.
I’ve always had slow ATV speeds with Infuse too.
Theoretical max WiFi speed on ATV is 866Mbps on 5Ghz AC. But, even in the same room, you won’t get very close to that with small devices. With my 4th Gen I got similar performance between 100M Ethernet and ac WiFi.
It’s really strange. I got the same issue here. under same internet environment at home, iPad and iPhone streaming from my vps up to 15MB/s，but only 4-6MB/s on my ATV. Same vps same source. No transcoding at all. That also leads to stuttering playback on my atv. but iPhone does not have this issue at all.
And yes, atv used to work without issues either!
Just to double check, you may want to make sure that the ATV is still connected to the right WiFi net. Occasionally when the ATV restarts after a OS update it will grab a different WiFi network if you have a dual band router. With the 5G band not having quite the range of the 2.4G band it may be too weak on the 5G and if your ATV was working on 5G and it switched to the 2.4G band it may not have the speed it did on the 5G.
Lastly, moving the ATV even a small amount can change things so try moving it a bit.
Hi, I am sure that apple tv is on 5G wifi
Then try the 2.4G network or if at all possible, try a temporary Ethernet connection to see if either of those help.
Thanks. Tried 2.4G wifi but no improvement. Tried Ethernet, there is some improvement but still way behind the performance on my iPad and iPhone. What would be the problem?
Maybe try resetting network settings on the Apple TV. I assume you tried restarting. I guess tvOS 15.1 might change things too
I tried resetting the whole apple tv and there is only slight improvement and yes it is tvOS 15.1 already😁
Did you try changing the smb type from auto to something else in infuse?
Yes. I have a local emby server setup on my nas for streaming super high bitrate videos. It works just great.