Xbox series X VRR is always grayed out.

That monitor doesn't have HDMI 2.1...it has HDMI 2.0 but that makes no difference as it is a 1440p monitor, not 4k.

enable freesync in the monitor setting first then restart everything.

Hi and thanks for reaching Microsoft Xbox gamer's community. My name is Josef.

I'm an Independent Advisor and a Microsoft Xbox user like you.

Hope you're doing great today despite this Crudyg123

Are you using the cable included with your Xbox console or a different cable, and may I know if you have connected the console to the HDMI 2.1 port on your TV?

And, which troubleshooting steps you have done so far to fix this issue?

I'll be waiting for your reply, greetings from another Microsoft user

Have you tried turning off VRR on the Series X?

I had the same issue using a Denon hdmi 2.1 AVR. I solved it using VRR with 120hz, but I have a hdmi 2.1 tv and a Series X, not One X. I guess you are stuck with 4k without vrr or full hd 120 and vrr. Another solution is to connect the Xbox directly to the tv and use arc/earc for audio, but One X does not support 4k 120hz, so you are stuck with full hd 120 if you use vrr.