ESXi

I'm currently porting Windows from a physical server to a VM under ESXi 7.0U3.

The issue I'm having concerns USB connections, in particular, connecting a physical USB on the VM host to a Digi Edgeport 416 "serial switch".  

I have created a virtual USB controller and 8 virtual USB devices on the Windows VM guest (I see the devices in the "Device Manager") but I'm not getting a connection to any devices connected to the Edgeport.  I know the connections between the Edgeport and the target devices are good because if I switch back to the physical server, I can connect to the target devices.

One thing I have noticed is that with the physical system is that if I issue the "mode" command when the server is attached to the Edgeport, I see "COMx" serial devices listed.  When I disconnect the Edgeport, these "COMx" devices go away.

When I connect the virtual system to the Edgeport, I do not see any COMx serial devices.

The Edgeport drivers on Windows are the most recent (5.70.105).

Does anyone have any idea what piece of the puzzle I am missing?

I've managed to proceed further in getting my Edgeport 416 (DB-9) switch to work with ESX but I don't have a comprehensive solution.

Some Edgeport 416 systems work and some don't. 

Edgeports that offer "2 USB devices" (when adding USB devices to a VM guest) work in that I can get access to all of the serial devices that are connected to the switch.

Those that offer "8 USB devices" (when adding USB devices to a VM guest) don't work and I can see some of the devices but not all at the same time.