Question about Samsung QE75Q950R

Hello, yes HDMI 2.1

Yes, HDMI 4 is a 2.1. HDMI 3(ARC) has been updated to eARC and is D. Atmos capable. My Xbox Series X runs on HDMI 4 with 4K in 120Hz. Problem-free. Freesync also works when the Xbox is connected directly to the TV. For the price, you have to buy the TV immediately. It used to cost 7000 and the picture is a dream.