4k videos only being shown in 1080p

[Ebb_And_Flow42]

I uploaded a video to YouTube in 4k but once it had finished processing the video was only available in 1080p, I checked the file to see if Premiere Pro had exported in 4k and it had.
video link
There's a link to the video in question.
If anyone can help me out it would be much appreciated.
Thank you.

 

[hang-the-9]

It does not matter what Premier rendered the video in, when you uploaded the video to YouTube did you see what options you had checked off?