If the game won't show your native resolution and you are playing on a 4K TV with HDR, you will have to turn off HDR on the TV (turning off HDR in Windows won't work), and then the game will allow you to select a higher resolution from the in-game options. Possible solutions include unplugging any extra monitors or setting the multi-monitor display mode in Windows to 'Computer Only'.
Such cases may be caused by the presence of multiple monitors attached to the computer, or attempting to play the game on an attached TV where larger resolutions may not be available. Some users have encountered issues such as not being able to set their native resolution the game resetting their chosen resolution to a lower one or the game's maximum available resolution being lower than their monitor's native resolution.
