Question about Verbatim PMT-14 Portable Touchscreen Monitor 14" Full HD 1080p Metal Housing

I have connected my new Verbatim PMT-14 monitor to a laptop via USB-C and to a desktop PC via HDMI. When only one or the other computer is running, everything is ok. When the desktop PC is running and I switch on the laptop, I can switch from the PMT-14 to the laptop (i.e. from the HDMI to the USB-C connection) via the menu. If I then want to switch back to the HDMI connection, this does not work. The monitor stays black briefly as if it were switching, but remains on the USB-C connection. Only when I unplug the USB-C cable does the monitor immediately switch to the HDMI connection, which is then the only remaining connection. Can anyone reproduce this? Thank you in advance for your support.