With my PC (Aspire E15 E5, Windows 10), the screen only works with an additional HDMI cable. The screen is supplied with power via the USB-C cable, but no signal is transmitted. Do I need to install a special programme on the PC so that the signal is also transmitted via the USB-C cable? The same question arises for my mobile: Motorola g7 with Android 10. Many thanks for any information. With best regards from Andreas Wildhaber