I got a 240hz monitor but it's only showing up as 120hz

[RicEcho]

Hi when I have a BenQ monitor and it's a 240 hz monitor. I saw it once on this screen - https://gyazo.com/961eb1ee47c289b9f561fe11f044143b but it doesn't show the 240hz option

 

[Rexper]

Make sure you are using either DisplayPort 1.2 or HDMI 2.0.
Which exact 1080ti are you using?

 

[RicEcho]

Make sure you are using either DisplayPort 1.2 or HDMI 2.0.
Which exact 1080ti are you using?

Okay but it said 240hz once tho?

 

[RicEcho]

Make sure you are using either DisplayPort 1.2 or HDMI 2.0.
Which exact 1080ti are you using?

I am using Strix gtx 1080ti