Trouble with a simple blink project

So im ruining a simple code script to blink 2 neopixel jewels. it has been working well on a arduino board. however, i needed to the board to be smaller so i swapped out for an Elegoo nano board.

however, now im getting odd results, on blinking, the LED’s turn white then back, the half go white but nothing seems to be no constancy in the results.

Does anyone have any thoughts to why and is there a way of fixing it?

the code.

#include <Adafruit_NeoPixel.h>


Adafruit_NeoPixel strip = Adafruit_NeoPixel(14, PIN, NEO_RGB + NEO_KHZ400);


void setup() {
  strip.begin();
  strip.show(); // Initialize all pixels to 'off'

}

void loop() {
  strip.setBrightness(5);
  strip.setPixelColor(0, 45, 255, 0);
  strip.setPixelColor(1, 45, 255, 0);
  strip.setPixelColor(2, 45, 255, 0);
  strip.setPixelColor(3, 45, 255, 0);
  strip.setPixelColor(4, 45, 255, 0);
  strip.setPixelColor(5, 45, 255, 0);
  strip.setPixelColor(6, 45, 255, 0);
  strip.setPixelColor(7, 45, 255, 0);
  strip.setPixelColor(8, 45, 255, 0);
  strip.setPixelColor(9, 45, 255, 0);
  strip.setPixelColor(10, 45, 255, 0);
  strip.setPixelColor(11, 45, 255, 0);
  strip.setPixelColor(12, 45, 255, 0);
  strip.setPixelColor(13, 45, 255, 0);    
  strip.show();
  delay(2000);
  strip.setBrightness(350);
  strip.setPixelColor(0, 25, 255, 0);
  strip.setPixelColor(1, 25, 255, 0);
  strip.setPixelColor(2, 25, 255, 0);
  strip.setPixelColor(3, 25, 255, 0);
  strip.setPixelColor(4, 25, 255, 0);
  strip.setPixelColor(5, 25, 255, 0);
  strip.setPixelColor(6, 25, 255, 0);
  strip.setPixelColor(7, 25, 255, 0);
  strip.setPixelColor(8, 25, 255, 0);
  strip.setPixelColor(9, 25, 255, 0);
  strip.setPixelColor(10, 25, 255, 0);
  strip.setPixelColor(11, 25, 255, 0);
  strip.setPixelColor(12, 25, 255, 0);
  strip.setPixelColor(13, 25, 255, 0); 
  strip.show();
  delay(2000);
}

I dunno, never used neopixel rings, but be sure to use [code] tags, not [quote] tags. Cause it's hard to read in italics.

Please tell us how you have the Neopixel Jewels wired (preferably a schematic).