Can't find HTML tags in code behind under impersonation

Question

I have an aspx page that inherits the IHttpHandler class. On page load I issued a call to an Impersonation class in which it renders the content under a different username than that currently logged in. But the problem is when impersonated I call a function back on the code behind in the aspx page that needs to access a div tag in order to insert content to it via an object tag and it doesn't find the tag anymore. Any clue as to why? Or to how am I able to build tags from the code behind in such a situation?

The impersonation function I used is based off of : https://www.codeproject.com/Articles/107940/Back-to-Basic-ASP-NET-Runtime-Impersonation.aspx

And this is the function that is called when impersonated within my aspx page:

    public void FUNCTION() //This is called from the impersonation function above
    {
        report = Session[Document];
        string url = "http://localhost/PATH" + report.toString();

        HtmlGenericControl objReport = new HtmlGenericControl();
        objReport.TagName = "object";
        objReport.Attributes.Add("data", url);
        Control cntrl = Page.FindControl("objReportFrame");
        if (cntrl != null)
            cntrl.Controls.Add(objReport);
    }