After going through the firmware, I understand that you added a vendor interface as a means to have the still capture trigger (0x88) in firmware.
Please undo the change i mentioned in my response 11 and keep the interface number = 0x03.
Now, the image shared in response 8 makes sense and the other interface is a vendor interface that needs to be binded to any vendor specific driver manually. You can also bind the interface to CyUSB driver and use it as a vendor interface by binding it to the driver located in the location: C:\Program Files (x86)\Cypress\EZ-USB FX3 SDK\1.3\driver\bin
You can select a driver according to your OS and OS architecture (32 or 64-bit) from the above folder.
The process of manually binding the cyusb3.sys driver to the interface is as follows:
1.) Right click on FX3 under 'Other devices' section of Device Manager and choose 'Update Driver Software'.
2.) In the pop-up window, choose 'Browse my computer for driver software'.
3.) Choose 'Let me pick from a list of device drivers on my computer'.
4.) Choose 'Show All Devices' and click Next.
5.) Click on 'Have Disk...'
6.) In the pop-up window, choose 'Browse...' and go to the following location: C:\Program Files (x86)\Cypress\EZ-USB FX3 SDK\1.3\driver\bin ( select the OS and whether x64 or x86)
7.) Choose "cyusb3.inf" and click Okay.
This will make the device enumerate again with a vendor interface and you can use control center to send the vendor command you want.