OK some more strange things about this 4K display. Besides really being washed out and inaccurate color-wise, it has another problem. It does not seem to advertise itself properly with DisplayPort.
On an older MacBook Pro 2010 that can display 2.5K properly on other monitors, like the ASUS 2.5K or the Benq 32″ 2.5K, this one only shows that 1080p is available. It sure looks like upscaled, but it doesn’t seem to advertise properly. So beware.
Also the Satechi USB C dongle doesn’t seem to output HDMI properly so neither the Monoprice nor the ASUS recognize it. Sigh!