PBP use on Dell U4320Q (linked to a Dell Optiplex PC)

Hello, I have a Dell OptiPlex PC with 3 DisplayPort outputs and 6 USB-A outputs. I have a Dell U4320Q monitor with 2 HDMI inputs, 2 DisplayPort inputs, and 1 USB-C input. I am trying to use the PBP (Picture-by-Picture) function to divide my screen into 4 display zones. However, I can only display the zones supplied by the DisplayPort cables. I have no display for the zones supplied by HDMI cables connected to a USB-A or DisplayPort adapter, and I have no display for the zone supplied by a USB-C cable