I then use the command

"DrawIcon(100, 780, (uint16_t *)Arrow_circle_down, 64, 64, true);"

together with the same drawIcon command for my other icons which are in an icon.h file I downloaded from the internet. All of the other icons display correctly but the icon I created displays as two small icons at the top and part of an unconnected icon at the bottom of the 64x64 square.

My working icon arrays look like this:
static const uint8_t SUNRISE64x64[8192] = {
0xff, 0xff, 0xff,........};

My created icon array array looks like this;
// array size is 4096
static const int8_t Arrow_circle_down[] = {
0xff, 0xff, 0xff,........};

I tried putting the array size 4096 in the square brackets but that made no difference.

The function drawIcon is:

void DrawIcon(int x, int y, const uint16_t icon, int dx /= 64/, int dy /= 64/, bool highContrast /= false/) {
for (int yi = 0; yi < dy; yi++) {
for (int xi = 0; xi < dx; xi++) {
uint16_t pixel = icon[yi * dx + xi];
if (highContrast) {
if (15 - (pixel / 4096) > 0) canvas.drawPixel(x + xi, y + yi, M5EPD_Canvas::G15);
} else {
canvas.drawPixel(x + xi, y + yi, 15 - (pixel / 4096));
}
}
}
}*

Why is the created icon not displaying correctly?