Hello,
You can take an example of connectEVE for easy understanding.
Data format and all I have used in arduino and it worked there and I have replicated here so I don't think it might show issue related to it. Even you can have a look at FT800 programmers guide. I am also using 4.3" color display.
After my connection and loading a program I even checked the VCC and ground pins on my GLCD t is getting proper voltage of 3.3V.
For best example you can have a look at connectEVE you will get a clear idea.
Thank you