Hi Rob!
I will try to help you, here some questions:
1) Can you tell us the Firmware version of the XBP24 that you are using?
2) Can you add the module with
XCTU digi tool?
3) When you execute the command in linux, have you the right permissions to open the port? (sudo command will be needed in some cases)(In windows you should execute XIG with administrator permissions)
4) What version of XIG are you using?
I have here the same board and I am able to add the module and work with it.
Looks like you have some problems to open the COMport
Regards