FastLED palettes by number - not working

/* Accessing palette via numbers instead of names. NOT WORKING!!!
 *
 * By: Andrew Tuline
 *
 * Date: January, 2021
 *
 * Reference: https://github.com/cloudwalking/tree/blob/master/tree/tree.ino
 *
 * There DOES, however appear to be a problem, because palettes[1] is black.
 *
 */

#include <FastLED.h>

#define ARRAY_SIZE(A) (sizeof(A) / sizeof((A)[0]))

#define LED_DT 12
#define COLOR_ORDER GRB
#define LED_TYPE WS2812
#define NUM_LEDS 30

#define BRIGHTNESS 64

struct CRGB leds[NUM_LEDS];                                   // Initialize our LED array.

const TProgmemRGBGradientPalettePtr palettes[] = {
  (TProgmemRGBGradientPalettePtr)PartyColors_p,  // 0 purple yellow red orange blue
  (TProgmemRGBGradientPalettePtr)CloudColors_p,  // 1 blue white
  (TProgmemRGBGradientPalettePtr)OceanColors_p,  // 2 blue cyan white
  (TProgmemRGBGradientPalettePtr)ForestColors_p, // 3 green blue
  (TProgmemRGBGradientPalettePtr)LavaColors_p,   // 4 yellow orange red black
  (TProgmemRGBGradientPalettePtr)HeatColors_p,   // 5 yellow orange red white
  (TProgmemRGBGradientPalettePtr)RainbowColors_p // 6 rainbow
  };

CRGBPalette16 currentPalette;


void setup() {
  Serial.begin(115200);
  LEDS.addLeds<LED_TYPE, LED_DT, COLOR_ORDER>(leds, NUM_LEDS);
  FastLED.setBrightness(BRIGHTNESS);
} // setup()


void loop () {
  uint8_t palette_num = (millis()/2000) % ARRAY_SIZE(palettes);
  currentPalette = palettes[palette_num];
  Serial.println(palette_num);
  fill_palette(leds, NUM_LEDS, 0, (256/NUM_LEDS)+1, currentPalette, 255, NOBLEND);
  FastLED.show();
} // loop()