Please go to the properties of the FX3 device (double click on the device) in the device manager and can you let me know what error code is reported.
- Please confirm that Cypress driver is installed from this link https://www.cypress.com/documentation/software-and-drivers/ez-usb-fx3-software-development-kit
- Please try programming FX3 with the USBBulksrcsink example firmware of the SDK and check that FX3 comes up as Cypress FX3 USB StreamerExample Device.
- If the device enumerates as expected in the above case and doesn't enumerate as expected with the custom firmware, please check the descriptors of the firmware.
- If the device is expected to enumerate as a composite device with the custom firmware, please check this KBA Adding Communication Device Class Interface to FX3 Firmware - KBA229099 and try unbinding the driver and rebind it.