This happens for me when I connect to a USB3 port. Try a USB2 port. (Quite ironic and silly for a USB3 devkit....)
Have you followed the JTAG debugging steps mentioned in the EzUsbSuite_UG.PDF provided with SDK (dafault path: C:\Program Files (x86)\Cypress\EZ-USB FX3 SDK\1.3\doc\firmware)?
Have you tried to load any example firmware to the RAM directly using USB boot method using the Control Center Application?
If yes, is the device enumeration fine in this case?
What is the firmware that you tried here?
Can you try USB Bulk Source Sink provided in the SDK (path: C:\Program Files (x86)\Cypress\EZ-USB FX3 SDK\1.3\firmware\basic_examples\cyfxbulksrcsink) by connecting to USB 2.0 and USB 3.0 port?