Why a menu item is collapsing before it's child item is clicked in iOS only and how to prevent it ?

I am working on mobileweb Selenium-Appium-Java test script development. The scenario is like this.

User clicks on 'Shop' hamburger menu
It opens 'Conduit' and other menu items
User clicks on 'Conduit' item, which opens the submenu items 'Steel Conduit', 'Aluminium Conduit' , plus many other items.
In iOS alone, while Android testing is running as expected, that after 'Shop' is clicked and 'Conduit' item has showed up, and even before 'Conduit' is clicked to see the 'Steel Conduit' item, the 'Conduit' is collapsing in to it's parent 'Shop'.
This is causing the WebElement for 'Steel Conduit' is failing to be located, rightfully so as it has been under 'Conduit' which has collapsed in to 'Shop' already.
I am using the following coding:--

                //'Shop' menu item under hamburger menu in the mobile
waitingDriver.until(ExpectedConditions.visibilityOfElementLocated(By.xpath("(//span[@class='toggle'])[2]"))).click();
                doWait(3000);
                // category item under 'Shop' menu item  
WebElement categoryElm = waitingDriver.until(ExpectedConditions.elementToBeClickable(By.xpath(String.format("//a[contains(text(),'%s')]",category))));
                doWait(3000);// sleep method

System.out.println("category Text="+categoryElm.getText()); // outputs Conduit
                elementActionsTap(categoryElm);
                if(null != sub_category) { 
                    // sub-category under category menu item
WebElement sub_categoryElm = waitingDriver.until(ExpectedConditions.elementToBeClickable(By.xpath(String.format("//a[normalize-space()='%s']",sub_category))));
System.out.println("sub_categoryElm Text="+sub_categoryElm.getText()); // supposedly output 'Steel Conduit'
                    elementActionsTap(sub_categoryElm);
                }   // end 'if'


/**
* The Tap method using W3C Actions class.
*/

public void elementActionsTap(WebElement elm) {
    int elmCenterX = elm.getLocation().getX() + elm.getSize().getWidth()/2;
    int elmCenterY = elm.getLocation().getY() + elm.getSize().getHeight()/2;
    PointerInput finger = new PointerInput(PointerInput.Kind.TOUCH, "indexFinger");
    Sequence tap = new Sequence(finger, 1);
    tap.addAction(finger.createPointerMove(Duration.ofMillis(0), PointerInput.Origin.viewport(), elmCenterX, elmCenterY));
    tap.addAction(finger.createPointerDown(PointerInput.MouseButton.LEFT.asArg()));
    tap.addAction(finger.createPointerUp(PointerInput.MouseButton.LEFT.asArg()));
    driver.perform(List.of(tap));
}

appium / appium-xcuitest-driver

Why a menu item is collapsing before it's child item is clicked in iOS only and how to prevent it ? #2472