Hi Alessandro
We haven't had this problem so far. Maybe it has something to do with the fact that the monitor is connected to an Xbox and not to a "normal" computer.
Best regards,
Christian

Hello Alessandro
Maybe it's the cable you're using. As far as I know, the HDMI cable does not support the maximum update rate.
Greetings Patrick

Could it be that, if you have Windows, Windows has changed the display settings? Open the display settings (desktop->right click->display settings) In the window that opens, search for "Advanced display/display settings" and open it. Now it should be possible to increase the refresh rate using the drop-down menu. If this does not work, search for "Show adapter properties for screen 1" in the Advanced Display/Display Settings window. In the newly opened window, you can now switch to the "Monitor" tab and theoretically increase the screen refresh rate there again.

I hope I was able to help you.
Lg