Xavier NX display problem

In hardware, I delete HDMI circuit on the Xavier NX developer kit and use official OS to flash module. The theory seems to just only one display, but actually, I find that there are two displays. One is conneted to DP which is really exist. Another is shown as ‘Unkown display’ in the display settings.
Which signal would cause the appearance?

Please also remove the HDMI part nvdipsplay from your device tree.