How do I properly set a display resolution of 1440p on a display that is 4k native?

[jasoncollege24]

System specs are at the bottom of this post. I'm trying to make my 4k display (3840x2160) show a resolution of 1440p (2560x1440), but I keep having issues. My last attempt showed the right resolution (apps showed the way I expected), but the background stretched beyond the screen (assumed to be the total 4k size), and the default panel was also not on screen (also assumed to be at the bottom of 4k). That attempt used the following Nvidia settings:

Resolution: 3840x2160 60Hz
Orientation: No rotation, No reflection
Position: Absolute +1920+0
ViewPortIn: 2560x1440
ViewPortOut: 3840x2160
Panning: 2560x1440
Primary Display: Yes

Any help would be greatly appreciated.

System Specs:
Desktop
System: TUF GAMING Z790-PLUS WIFI
Primary OS: Kubuntu LTS
Secondary OS: Windows 10 Pro
CPU: Intel Core i9-13900K
RAM: 32GB Dual Channel
Graphics: NVidia GeForce RTX 3090-TI (24GB)
Drivers: Proprietary drivers 580
Sound: RealTech HD Audio
Display 1 (Secondary): DELL 1080p Touch Monitor (DisplayPort)
Display 2 (Primary): Vizio 43" 4k UHD Home Theater Display (HDMI)
Display 3 (Tertiary): HP 1080p Display (DisplayPort)
Network type: Wi-Fi/Ethernet (Interchangeable, but almost exclusively Ethernet with gigabit speeds)
Storage Space: LOTS
Control type: Keyboard, Mouse, and PS5 Controller