LED strip on chip ws2811 doesn't work correct on Raspberry Pi 3b using Pi4j

Question

I use Pi4j on a Raspberry Pi to control a LED strip. It is made on chip ws2811. I have rewrote the example from the official homepage to have the ability to switch on some LEDs. The color is only white. I set the values of the first LED (parameter1) and last LED (parameter2) from external classes. When I call the function execute() I want that the LEDs with numbers from parameter1 to parameter2 will be switched on. But in the reality all the LEDs are shifted on one LED to end. For example: when I set parameter1 on 0 and parameter2 on 4 the LEDs from 1 to 5 will be switched on. But must be LEDs with numbers 0 to 4. Yesterday after this command the LED with the number 0 flashed red and from 1 to 5 - white. Help me please find the error.

public class LedChainManager extends Manager{
    private LinuxRaspberryPiGpioManager linuxRaspberryPiGpioManager;
    private static LedStrip ledStrip;
    private final int leds = 10;
    private int parameter1, parameter2;

    public LedChainManager(LinuxRaspberryPiGpioManager linuxRaspberryPiGpioManager) {
        this.linuxRaspberryPiGpioManager = linuxRaspberryPiGpioManager;
        init();
    }

    private void init() {
        ledStrip = new LedStrip(linuxRaspberryPiGpioManager.getPi4j(), leds, 1);
    }
    
    protected void delay(long milliseconds) {
        try {
            Thread.sleep(milliseconds);
        } catch (InterruptedException e) {
            Thread.currentThread().interrupt();
        }
    }

    public void setParameter1(int parameter1) {
        this.parameter1 = parameter1;
    }

    public void setParameter2(int parameter2) {
        this.parameter2 = parameter2;
    }


    public void execute() {
        Logger.logGpio("LED colors changing started");
        ledStrip.allOff();     //Sometimes some LEDs stay switched on or start to flash red
        delay(5);
        ledStrip.allOff();     //I clear all the LEDs again. 
        if (parameter1 <= parameter2 ){
            if (parameter1 == 0 && parameter2 == 0){    //When parameter1 and parameter2 are 0 the LED strip must be switched off
                Logger.logGpio("All LEDs were switched off");
            }
            else {
                long startTime = System.currentTimeMillis();
                if (parameter1 >= 0 && parameter2 <= 9) {
                    for (int i = 0 ; i < leds; i++){
                        if (i>=parameter1 && i <= parameter2) {
                            ledStrip.setPixelColor(i, PixelColor.WHITE);
                        }
                    }
                    ledStrip.render();
                }
                Logger.logGpio("LED strip colors were changed in " + (System.currentTimeMillis()-startTime) + " milliseconds. LEDs from: " + parameter1 + " to " + parameter2 + " flash");
            }
        }
    }

    public void dispose(){
        ledStrip.close();
    }
}