Question Xiaomi TV not true 4k panel?

[hotfusion]

Hi,
I recently bought a Xiaomi Mi TV 50 inch, 4k HDR. I don't connect it to anything but a local cable provider. So, since it's a smart TV, I tried watching an Youtube 4k sample video, and it wasn't as sharp as I expected it to be honestly. I could clearly see the individual pixels on the video and general texts (such as texts in settings) seems low res. So I downloaded Aida64 to know the complete specs of the TV, and in the display section, Aida64 mentions that it has 1920x1080 pixels. Why would this be? it seems my suspicion was right but at the same time I don't think a popular brand such as Xiaomi would display wrong specs on their website.

I don't have any prior experience on 4k displays and not much experience with TVs in general. I can't find an option to change resolution anywhere, do I need to connect it to third party devices as such as Laptops/PCs etc. to get the 4k resolution? If anyone have an idea to what's going on with my TV, please help me. I am completely at lost here. Thanks

 

[Mtop]

Do you have a copmuter that will output 4k@60hz HDR? Use the Tv as a monitor and stream 4k from various sites including youtube then compare.
Youtube may not be streaming 4k. When I access a HD movie on youtube it somehow turns on windows hdr prior to streaming.