enter image description here
The stars in the first column of each row appear to be misaligned or have a different background color compared to the rest of the stars in the grid.
The issue seems specific to the first star in each row, as the rest of the stars align correctly.
here is the relevant code,

import pygame
import sys
from star import Star
from random import randint

def check_events():
    """Check events in main module such as mouse and keyboard movement"""
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            sys.exit()

def draw_star(star):
    """Draw the star on the screen top left corner"""
    star.blitme()

def get_number_star(star_width):
    """Number of stars in a row"""
    available_x = 800 - (2 * star_width)
    no_x = int(available_x / (2 * star_width))
    return no_x

def get_number_rows(star):
    """Number of rows of stars"""
    star_height = star.rect.height
    available_y = 600 - 3 * star_height
    number_rows = int(available_y / (2 * star_height))
    return number_rows

def create_star(number_x, screen, stars, row_number):
    """Create and add a star at a specific position"""
    star = Star(screen)
    star_width = star.rect.width
    star_height = star.rect.height

    # Position calculation
    star.rect.x = star_width * number_x
    star.rect.y = star_height * row_number

    stars.add(star)

def create_grid(screen, star, stars):
    """Create a grid of stars"""
    number_stars_x = get_number_star(star.rect.width)
    number_rows_y = get_number_rows(star)

    for row_number in range(number_rows_y):
        for number_x in range(number_stars_x):
            create_star(number_x, screen, stars, row_number)

What did I try?
= Checked for any initialization issues or positioning anomalies.