U2722DE, KVM without DisplayPort

I am super confused and hoping someone can help. I cannot get the USB switching function working on the U2722DE I have just bought. I have;

• Monitor; U2722DE
• Laptop Work with ports;  USB-C, USB-A
• Laptop Personal with ports; HDMI , USB-A, USB-C (USB-C port has no video out support)

I have the set up as;

• Laptop Work --> USB-C to USB-C --> U2722DE (Port 5 - Page 14 *)
• Laptop Personal --> HDMI to HDMI --> U2722DE  (Port 3 - Page 13 *)
• Laptop Personal --> USB-A to USB-A --> U2722DE (Port 8 - Page 14 *)
• USB-A Mouse Receiver (Port 10)
• USB-A Keyboard Receiver (Port 11)
  
  
  

I can switch between the monitor input, but I cannot seem to get the USB switching to work. When I try to access the USB-Switch function I get:

"USB switch function is only available when PIP/PBP function is enabled. Ensure that your input devices are connected to the monitor"

The mouse and keyboard will work fine with Laptop Work over USB-C.

Does USB switch not work over USB-A, what are my options if not?

Any insight gratefully received!

* Based on image on page 13 from this https://dl.dell.com/manuals/all-products/esuprt_electronics_accessories/esuprt_electronics_accessories_monitor/esuprt_monitor_ultrasharp_u_series/dell-u2722de-monitor_user's-guide_en-us.pdf