Have been experiencing buffering issues with YouTube for the last 3 days no matter what time I've tried. I've not tried past 1 am as I am not sacrificing my life just to watch a couple of YouTube videos.
They work fine on my Optus 4G connection, just not my ADSL2+ at home.
It strikes me as unlucky that YouTube would be having problems with their infrastructure and not give a notice, but I would not be surprised if that was the case with Optus.
i think optus prioritism netflix traffic some what. But if you can get 1090p on netflix then youtube shoudd able to get at least 720p. I know whenever, i start a video on youtube its quite low and slowing upto the video's resolution. Try to manually chage the resolution to the max and see if it is watchable. Have you done a speed test via a Lan cable and see what speed you are getting? Maybe too many people is watch the same cat video as you at the same time and youtube not dishing it fast enough. ..just a thought.
Also, how are you watching the youtube videos, via computer, ipad, smart tv etc? Maybe a new 4K OLED TV will fix the problem.
By the mear fact you suggested that a 4K OLED TV 'might' solve the problem, I know you know nothing about what you are speaking.
I'm using a PC via LAN cable and get 10mbps on my ADSL2+ connection. I believe the problem is either the way Optus prioritises traffic, or the way YouTube does. Yes, I did try manually changing the settings, I'm not your Grandma, mate.
Not a fan for a new Oled tv. Prehaps a new iPhone X can help with your problem.