TFT Touch display HX9347 I - cant start up, only white screen

Install / Update MCUFRIEND_kbv via the Library Manager.

From the extras/mcufriend_how_to.text:

HX8347-I 240x320  ID=0x9595 #define SUPPORT_8347D

Edit MCUFRIEND_kbv.cpp:
from

//#define SUPPORT_8347D             //HX8347-D, HX8347-G, HX8347-I +520 bytes, 0.27s

to

#define SUPPORT_8347D             //HX8347-D, HX8347-G, HX8347-I +520 bytes, 0.27s

David.