Can't get led strip to work properly

[amadeok]

Hello
I got a 5 meter led strip from aliexpress, it seems it is a ws2811 strip where each chip control 36 leds, total 720 leds.
I can't get it to work properly, when i tell it to do red, it does green for example, and it's not always consistent, meaning it sometimes just does some random color even i didnt program it to make a different color.
Also the first chip just does something different, its always different from the rest.
I've been using the FastLED library

I also tried the Adafruit_NeoPixel library, with this one sometimes it stutters

This strip shares ground and 12v to a different strip, a ws2815, this ws2815 seems to work fine, i'm not sure if having it connecting like this may be causing problems

I tried different pixel format like BGR and RBG, none seem to fix the issue

Here's the test sketch

#include <FastLED.h>
#define LED_PIN 25    // Replace with the pin number you used for DATA connection
#define NUM_LEDS 100  // Replace with the number of LEDs in your strip
CRGB leds[NUM_LEDS];
void setup() {
  FastLED.addLeds<WS2811, LED_PIN, GRB >(leds, NUM_LEDS);
  FastLED.setBrightness(255);
}
void loop() {
  
  for (int i = 0; i < NUM_LEDS; i++)
    leds[i] = CRGB::Red;
  FastLED.show();
  delay(500);

  for (int i = 0; i < NUM_LEDS; i++)
    leds[i] = CRGB::Green;
  FastLED.show();
  delay(500);

    for (int i = 0; i < NUM_LEDS; i++)
    leds[i] = CRGB::Blue;
  FastLED.show();
  delay(500);

  for (int i = 0; i < NUM_LEDS; i++)
    leds[i] = CRGB::Black;
  FastLED.show();
  delay(1000);
}

with that sketch, this is what the strip does:

WS2811 problem

Any help? thanks

[xfpd]

@amadeok

FastLED.addLeds<WS2811, LED_PIN, GRB >(leds, NUM_LEDS);

Try RGB (rather than GRB) in this line...

[amadeok]

Hi thanks for reply,
this is the link
FCOB LED Light Strip Pixel Addressable 630 720 LEDs RGB Dream Full Color 12mm DC12V 24V WS2812B High Density Flexible COB Lights - AliExpress

this is my order,

from there i see that the type i ordered is "720leds, DC12V Black PCB, 5m"