Even though the $399 S2722QC has three video in ports that could support three PC, the S2722QC does not have the necessary "second" USB-C upstream port. Nor did it include a USB-C to USB-A cable. So PC #1 connected to the S2722QC #5 USB Type-C upstream port will show video and give PC #1 access to the S2722QC USB-A downstream ports. But any PC connected to the S2722QC HDMI ports will NOT have access to the S2722QC USB-A downstream ports. To do what you want, you needed to have purchased the $584 U2723QE which does have the "second" USB-C upstream port.
Hi, I have a Dell 27" 4K-USB-C-Monitor – S2722QC with keyboard and mouse connected to the downstream USB ports. If I connect my notebook with the USB-C cable everything is fine. I get video, audio and USB upstream functionality. My problem is that I have a second desktop PC I also sometimes would like to connect. It has to use HDMI for video because its USB-C port doesn't support a video signal. How can I get the upstream USB functionality then? I tried to connect the USB-C cable and thought the keyboard and mouse would work then but they didn't. Any ideas how to solve this? I would like to keep the keyboard and mouse connected to the monitor to reduce cable clutter as much as possible.
S2722QC, USB-C upstream without video signal possible?