Poor resolution on PC. Less than 720p ..

I recently got a subscription for Disney Plus. They say you can stream in 4k. I stream on my PC and have a 2k TV. You dont get an option to go higher than 720p on a computer. Dont get disney plus on a computer if you want high resolution because they dont allow you higher than 720p. Its shocking actually. I can stream Netflix on a PC at 4k. Looks amazing, not like this pixel art I am getting on Disney Plus.