DIAGNOSIS The Nintendo Switch outputs a maximum of 1080p in docked mode unless the game and system settings specifically support 4K. The monitor is just displaying the signal it receives.
FIX The Switch itself cannot output a native 4K signal for games. The monitor's 4K upscaling is what you need to engage.
- Ensure your Switch is in the dock and the dock is connected to the monitor via a High-Speed HDMI cable (use the one that came with the monitor or a certified one) to the monitor's HDMI 2 or HDMI 1 port.
- On the monitor, press the joystick. Go to Picture > Display Mode. Select Display. This enables the monitor's internal scaler to upscale the 1080p signal from the Switch to fit the 4K panel.
- On the Switch, go to System Settings > TV Settings > TV Resolution and set it to Automatic or 1080p.
IF THAT DIDN'T WORK Try a different HDMI cable. A poor-quality cable may not handshake properly, forcing the Switch to a lower resolution like 720p.
HEADS UP This is upscaled 4K, not native. It will look sharper than a 1080p monitor but not as detailed as a native 4K source like a PS5 or PC. For the best motion clarity with the Switch, also go to the OSD under Picture > AMA and set it to Premium.