Galen/Selenium : Paypal Login process

Question

For desktop, On click on paypal btn, new window open on which user fill their crediantials and then it goes back to original page.

To handle this, i wrote following code

    winHandle = driver.getWindowHandles();
    console.log("no. of window "+winHandle.toArray().length); //1 for mobile
    handle = winHandle.toArray()[winHandle.size() - 1];
    console.log(handle);
    previousHandle = winHandle.toArray()[0];
    //On paypal login, a new window will open. Below code will handle the window switching. But this is not happening with mobile
    driver.switchTo().window(handle);
    console.log("switched to paypal window");
    paypalLogin = new PayPalLoginPage(driver);
    paypalLogin.proceedWithSandBoxPurchase();
    //switch to origin window
    driver.switchTo().window(previousHandle); 

But problem with android and iphone is, on click of paypal btn no other window is open but paypal page appears.

When i try to find any element of this paypal page i get element not found exception.

Has someone faced this issue paypal login process in selenium or galen framework for mobile testing in saucelabs ? And how it solved?