assert.istrue returning null value

When I run my selenium tests using .net frame and C# I am getting Message: Object reference not set to an instance of an object.

{
    landingPage = new LandingPageCode(driver);
    driver = new ChromeDriver();

    driver.Url = ("My URL");

    IWebElement element = landingPage.PageTitle; 

    Assert.IsTrue(element.Displayed);
}

My base code is below, which is being referenced within the above Iwebelement:

[FindsBy(How = How.TagName, Using = "PageTitle")] 
public IWebElement PageTitle{ get; set; }

I also get the same issue when I write the test as per below without the element aspect.

{
    driver = new ChromeDriver();
    landingPage = new LandingPageCode(driver);

    driver.Url = ("My URL");

    Assert.IsTrue(landingPage.PageTitle.Displayed);
}