I have same issue on my 2018 series 65Q7FN since last 2 months (after 1310.4 update). I tried contact with both Samsung support and YouTube support but they did not suggest anything properly. Samsung customer agent said wait for a new update (no answer for how much time it will take?) and still no update from YouTube support yet. This is unacceptable issue. I'm using my TV only with YouTube and gaming consoles only and now I am not able to watch any 2K (1440p) or 4K (2160p) videos on YouTube TV app.
Even I bought YouTube Premium to be able to watch live TV channels (I'm living in US and watching Turkish channels live on YouTube) on my pretty Samsung TV, now my 2nd cheap/budget Roku TV is able to play all 2K/4K videos on YouTube app but my Q7FN is not able to play. Need software update or hotfix immediately!
I am from Romania (Europe) and I have the same problem with 2 Samsung NU7402 TVs.
I also tried with another router on both 2.4 and 5 Ghz wireless connections and I had the same problem.
When the TV is connected to the internet by cable everything is working fine.
I also tried to watch videos using the Youtube app on a Playstation 4 and everything is working fine on wireless and over the cable.
So I am thinking the problem is with the TV and the Youtube app installed on the TV only when the TV is connected to the internet over WIFI.
I hope Samsung will fix this:)
same problem for me on q6fqe55
version web_20201208_00_RC04 KANYM2 1310.4
Wifi speed is very good, but video switch in 360p regulary...
and recently, a new issue with in-video advertise (when i click ok to "pass" advertise, the app switch to next video on playlist)
Samsung please help or inform youtube to have a fix.
The whole thing is a bit of a mess...
I bought a Chromecast with Google TV to get around it, but they suck as they have fixed frame rate...
one thing that may help though - over the weekend a "Movies and Shows" tab appeared, after that - mine seems fine - still on RC04
so, hopefully those of you with issues still will get that pop up on the left, and if you're like me after that, it should be business as usual.
Seem to be good after reset of network settings and reset of smart hub on QE55Q6FNAT
(to reset smart hub, make sure you are on TV source and go to settings, support, auto test and reset smart hub.
I'll reply to my post if the bug persist.
Having the same issue here on a 55 inch NU7400. 4k videos and some 1080p videos randomly drop down to 360p, despite having a fast, stable 150Mb connection. This is really unacceptable. It has been going on for almost 2 months, and Samsung don't seem interested at all in fixing it. My next TV definitely will NOT be a Samsung.