Execute Task.Run() in ASP.NET ActionResult without waiting for result

Question

Below is the function where I am trying to execute a function in the background and then carry on without waiting for a result from it.

When debugging the task itself is executed but the actual function within it does not. The rest of the code then carries on like normal.

What could be the issue as there is no error produced after that to indicate otherwise?

This is on a page load.

public ActionResult ExceptionReport(int? id)
{
    var ExceptionList = db.Invoices.Where(m => m.ExceptionFlag == true && m.GlobalInvoiceID == id);

    if (ExceptionList.Count() == 0)
    {

        globalInvoice.Status = "Exception Verification";
        db.Entry(globalInvoice).State = EntityState.Modified;
        db.SaveChanges();

        Task.Run(() => ExceptionFinalTests(globalInvoice)); //Function To run in the background



        TempData["warning"] = "Verifying all exceptions fixed. A notification will be sent when the verifications are complete.";
        return RedirectToAction("Index", "GlobalInvoices");
    }

    return View(ExceptionList);
}


   private void ExceptionFinalTests(GlobalInvoice globalInvoice)
    {
        RunTests(globalInvoice, true);

        decimal TotalPaymentAmount = db.Invoices.Where(m => m.GlobalInvoiceID == globalInvoice.Id).Sum(m => m.Invoice_Amount) ?? 0;
        }

        GlobalInvoicesController globalInvoicesController = new GlobalInvoicesController();

        var ApproverList = globalInvoicesController.GetUserEmailsInRole(globalInvoice, "Reviewer");

        globalInvoicesController.Dispose();

        var exceptionExistCompulsoryTest = db.Invoices.Where(m => m.ExceptionFlag == true && m.GlobalInvoiceID == globalInvoice.Id);

        if (exceptionExistCompulsoryTest.Count() > 0)
        {
            try
            {
                string baseUrl = ConfigurationManager.AppSettings["site"];

                EmailExtension emailExtension = new EmailExtension();

                foreach (var approver in ApproverList)
                {
                    string approvalLink = baseUrl + "/Invoices/ExceptionReport/" + globalInvoice.Id;

                    StringBuilder mailbody = new StringBuilder();
                    mailbody.AppendFormat("Hi<br/>");
                    mailbody.AppendFormat("There are " + exceptionExistCompulsoryTest.Count() + " exceptions for invoice #" + globalInvoice.Id + "that need attention before proceeding. - <a href='" + approvalLink + "'>Click Here</a> <br/><br/>");

                    mailbody.AppendFormat("Exception Count: {0}<br/>", exceptionExistCompulsoryTest.Count());
                    mailbody.AppendFormat("Invoice Amount: {0}<br/>", TotalPaymentAmount.ToString("C"));
                    mailbody.AppendFormat("Reviewed By: {0} <br/>", "");
                    mailbody.AppendFormat("Approved By: {0} <br/>", "");

                    EmailVM emailVM = new EmailVM()
                    {
                        Subject = "Invoice - #" + globalInvoice.Id,
                        EmailAddress = approver,
                        Message = mailbody.ToString()
                    };

                    emailExtension.SendEmail(emailVM);
                }
            }
            catch (Exception ex)
            {
                LogWriter.WriteLog(ex.Message);
                LogWriter.WriteLog(ex.StackTrace);
            }
        }
    }


    private void RunTests(GlobalInvoice globalInvoice, bool retestFlag = false)
    {

        List<Invoice> invoices;
        var vendorTests = globalInvoice.Vendor.VendorTests;
        string[] testsToRun = vendorTests.Split(',');

        if (retestFlag == true)
        {
            if (globalInvoice.Vendor.VendorHasHierarchy == true)
            {
                testsToRun = new string[] { "Account Number", "Hierarchy" };
            }
            else
            {
                testsToRun = new string[] { "Account Number" };
            }
        }

            using (var context = new MyContext())
            {
                invoices = context.Invoices.Where(m => m.GlobalInvoiceID == globalInvoiceToTestID).ToList();
            }


        foreach (var test in testsToRun)
        {
            if (test == "Account Number")
            {
                LogWriter.WriteLog("Starting Account Number Check : Invoice Batch ID - " + globalInvoice.Id);
                AccountNumberCheck(invoices, globalInvoice.VendorID);
                LogWriter.WriteLog("Account Number Check Complete : Invoice Batch ID - " + globalInvoice.Id);
            }
            if (test == "Hierarchy")
            {
                LogWriter.WriteLog("Starting Hierarchy Check : Invoice Batch ID - " + globalInvoice.Id);
                BillingHierarchyCheck(invoices);
                LogWriter.WriteLog("Hierarchy Check Complete : Invoice Batch ID - " + globalInvoice.Id);
            }
        }
    }