I think something is wrong with this LCD board. This is because in my case the display works sometimes perfectly with ILI9481 driver but after some times somthing hanges and start to flickering. It looks like chip charging problem. Anyway I solved the problem with flickering by tuning ILI9488 registers. Simply you have to change the initlcd.h for ili9481 driver in UTFT library.
enter code here
case ILI9481:
LCD_Write_COM(0x11);
delay(70);
LCD_Write_COM(0x38);//Idle Mode OFF
LCD_Write_COM(0x13);//Normal mode
LCD_Write_COM(0x36); // Memory Access Control crucial
LCD_Write_DATA(0x0A);
LCD_Write_COM(0x55);
LCD_Write_DATA(0x22);//High enhancment of CE ratio
LCD_Write_COM(0xB1);
LCD_Write_DATA(0x70);
LCD_Write_DATA(0x10);
LCD_Write_COM(0xB4);
LCD_Write_DATA(0x10);
LCD_Write_COM(0xB5);
LCD_Write_DATA(0x00);
LCD_Write_DATA(0x12);
LCD_Write_COM(0xB6); // Display Function Control
LCD_Write_DATA(0x00);
LCD_Write_DATA(0x21); // 0x42 = Rotate display 180 deg.
LCD_Write_DATA(0x3B);
LCD_Write_COM(0xC0);
LCD_Write_DATA(0x1F);//0X1F
LCD_Write_DATA(0x01);//0X10
LCD_Write_COM(0xC1);
LCD_Write_DATA(0x00);
LCD_Write_DATA(0x10);
LCD_Write_COM(0xC2);
LCD_Write_DATA(0x00);//0X44 lower better
LCD_Write_COM(0xC4);
LCD_Write_DATA(0x00);//0X10
LCD_Write_COM(0xC5);
LCD_Write_DATA(0x00);//0X10
LCD_Write_DATA(0x80);//optimum
LCD_Write_DATA(0x80);//0X10
LCD_Write_COM(0x3A);//Interface Pixel Format
LCD_Write_DATA(0x55);
LCD_Write_COM(0x2A);//Column Address Set
LCD_Write_DATA(0x00);
LCD_Write_DATA(0x00);
LCD_Write_DATA(0x01);
LCD_Write_DATA(0xDF);//320
LCD_Write_COM(0x2B);//Page Address Set
LCD_Write_DATA(0x00);
LCD_Write_DATA(0x00);
LCD_Write_DATA(0x01);
LCD_Write_DATA(0x3F);//480
delay(60);
LCD_Write_COM(0x29);//Display ON
delay(30);
LCD_Write_COM(0x2C);//Memory Write
delay(30);
break;