Intel UHD Graphics 630 capability to use Quad High Definition (QHD).
Can Intel UHD Graphics 620 run QHD (Quad High Definition) resolution using a USB-C to DP cable on a laptop with a USB 3.1 Type C port?
The graphics driver and graphics processing unit (GPU) can display 4K 4096x2304@60Hz resolution over DisplayPort™ (DP) 1.2 or HDMI® 2.0. When bandwidth and system configuration allow it, the GPU will display any resolution equal or lower than the Max Resolution supported by the processor (usually 4096x2304@60Hz) that is also supported by the display, for instance, UHD, QHD, 2K, FHD, etc,.
If you are interested in knowing if your display is capable of working under any other specific combination of resolution + refresh rate + color depth (e.g. 2560x1440@60Hz8bpp) also known as "Supported Modes or Video Modes", check the user manual or technical documents for your display or contact the manufacturer for this information.
Check this link to determine Maximum Supported Resolution on Intel® Graphics Technology.