Verifone Vx670 displaying with upper padding in pos LCD screen

Question

I’m working on Verifone Vx670 Point OF Sale(POS) terminals but I have the following situation :-

I downloaded the same code to two “Verifone Vx670” POS terminals. The code should display a menu for the POS user using this code:-

#define DYNAMIC_ROW_SIZE    25
char caTemp[DYNAMIC_ROW_SIZE] = "";
g_RowCount = 8;
for (i = 0; i < 4 && i < g_RowCount; i++)
{           
    memset (caTemp, 0x00, sizeof(caTemp));
    memcpy (caTemp, &g_DISPLAY_DATA[((g_DISPLAY_INDEX * 4 + i) * DYNAMIC_ROW_SIZE)], DYNAMIC_ROW_SIZE);
    write_at(caTemp, strlen(caTemp), 21 - strlen(caTemp), (i*2)+2);
}

I find that one of POS terminals is displaying the menu well as shown in figure Vx670_Working.jpg Vx670_Working.jpg

But the other one is display the menu with upper padding as shown in figure Vx670_Error.jpg

Vx670_Error.jpg

I don’t know why the second terminal displaying this upper padding before the menu.

Can anyone please help me to figure out the issue