HDMI to DisplayPort on monitor/tv that doesn't support HDMI 2.0.

Make sure also that the monitor supports, HDMI Displayport 2.0 as that what the Xbox One S and Xbox One X use, I believe that the standard Xbox One only uses HDMI Displayport 1.4,

Its possible that the monitor only supports HDMI Displayport 1.4,

Its possible that you're TV has HDMI Displayport 2.0, which could be the reason it works on the TV but not the monitor.

As far as I know, there are (expensive) active adapters that convert HDMI to DisplayPort, but they are only converting HDMI 1.4 to DP signals. There will need to be adapters that support HDMI 2.0, but I have yet to see one anywhere in the market.

Keep in mind that the conversion between HDMI and DisplayPort only goes in one direction, so please do not buy those cheaper passive adapters that convert DisplayPort to HDMI, as they will absolutely not work.

Your Samsung monitor will have to support HDMI 2.0 to drive 4K with the Xbox. If there are no settings to turn on 4K resolution over HDMI or “enable HDMI 2.0”, then your monitor may only support HDMI 1.4 (which technically drives 4k@30Hz, but the Xbox will
not use this). I am unsure of what model you have, but the supported resolutions over each input are typically listed in the monitor’s manual. I’ve encountered this exact question before, and honestly the only practical solution here is getting a new monitor
that has HDMI 2.0 and FreeSync.

Hello!

For 4K TVs, I think 120 hz with 2.0 hdmi is the maximum that the system will request. Now, for 8K TVs, 144hz with hdmi 2.1 it is necessary. So do not worry.

Hdmi 2.0 can only support 4K at 60hz or 1440p ( 2K ) at 120hz, Hdmi 2.1 will allow 4K at 120hz.

I'm also hoping that the console has a Displayport 1.4, for 4K at 120hz to use on 4K 144hz monitors

I'm saying that HDMI to displayport adapters are pointless to use, and if you were to use one , you'll still only be getting 60hz.

you want to connect the HDMI port of the Xbox console to a HDMI port on the monitor or TV for the best outcome,

because the Xbox One X does not have a displayport on the console, you can't go displayport to displayport,

so the only choice is HDMI to HDMI, i personally would not go HDMI from the console to displayport on the monitor via an HDMI to displayport adapter,

when connecting to a monitor it's best to go straight...

HDMI to HDMI

or

Displayport to Displayport

never

HDMI to Displayport via an adapter.

Like most monitors, it achieves its specs by overclocking.

Xbox relies on the supported resolutions that the monitor communicates to it like most consumer electronics devices.

I cannot find any literature that tells me the HDMI version in the monitor, but as the vast majority of them prioritize DisplayPort for performance and leave HDMI to 1.4, I would say that is likely the issue since HDMI 1.4 taps out at 1080 with high refresh.

Since DisplayPort is not bidirectional, an HDMI-DP adapter will not work. You'll need to exchange the display for one that supports at least HDMI 2.0