2:2 pulldown is what your TV can do in Real Cinema mode. It just means that for each frame, it displays the frame twice in 1/23.976 seconds. The final refresh rate of the display ends up being ~48Hz.
From what you describe, it sounds as if your PC’s refresh rate is not being set to 23Hz or 24Hz. You can perform a quick check by simply setting your desktop display refresh rate to 23Hz and observing that the Real Cinema option is enabled.
