Running multiple EVAL-ADT7x20EBZ Eval Boards

I am trying to use 5 ADT7x20 Eval Boards(with adt7420 external board) to monitor the temperature at 5 locations within a room. However, when I connect more than one ADT7x20 to the computer via the usb cable and run the software, sometimes it shows "USB communication failed".

However, this error sometimes do not show up if I changed the sequence of plugging in usb ports and opening up new process of the software. Moreover, this error sometimes show up and sometimes do not even if I follow that exact same sequence. Is there any way to reliably operate more than one of these Eval Boards?

Thanks