HttpContext.Current null в асинхронном режиме после вызовов ожидания

HttpContext.Current null в асинхронном режиме после вызовов ожидания.

Вот мой код:

if (!string.IsNullOrEmpty(securityGroupName))
{
    // To remove the domain name from the security group name.
    string securityGroupDisplayName = securityGroupName.Split('\\')[1];
    string serviceSecurityGroupId = await this.graphApiClient.GetGroupIdAsync(securityGroupDisplayName).ConfigureAwait(false);

    if (!string.IsNullOrEmpty(serviceSecurityGroupId))
    {
        Task securityGroupRoleAddTask = this.CheckMembershipAndAddRole(serviceSecurityGroupId, userId, securityGroupName);
        Task flightAdminRoleAddTask = this.CheckMembershipAndAddRole(FlightAdminSecurityGroupId, userId, FlightAdminRoleName);
        Task.WaitAll(securityGroupRoleAddTask, flightAdminRoleAddTask);
    }
    else
    {
        LoggingUtilities.Logger.TraceInformation("Azure AD id does not exist for the security group: {0}.", securityGroupName);
        await this.CheckMembershipAndAddRole(FlightAdminSecurityGroupId, userId, FlightAdminRoleName).ConfigureAwait(false);
    }
}
else
{
    LoggingUtilities.Logger.TraceInformation("Security group name is not valid, checking for flight admin role for the user: {0}.", userAlias);
    await this.CheckMembershipAndAddRole(FlightAdminSecurityGroupId, userId, FlightAdminRoleName).ConfigureAwait(false);
}

// Add the flight privileged users role to be able to verify the user is authorized for the role.
string flightPrivilegedUsersRoleName = RoleRepository.Instance.GetByName(Constants.FlightPrivilegedUsersRoleKey).Name;
if (!this.roles.Contains(flightPrivilegedUsersRoleName, StringComparer.OrdinalIgnoreCase))
{
    LoggingUtilities.Logger.TraceInformation("Adding flight privileged users to roles list for the user: {0}.", userAlias);
    this.roles.Add(flightPrivilegedUsersRoleName);
}

if (userAlias != null)
{
    LoggingUtilities.Logger.TraceInformation("Check security group memberships and assign roles for the user: {0}.", userAlias);
    var newPrincipal = new GenericPrincipal(new GenericIdentity(userAlias), this.roles.ToArray());
    Thread.CurrentPrincipal = newPrincipal;
    HttpContext.Current.User = newPrincipal;
}

Рекомендации по поводу следующих записей в записях web.config не помогли:

<system.web>
    <compilation debug="false" targetFramework="4.5" />
    <httpRuntime targetFramework="4.5" enableVersionHeader="false" requestPathInvalidCharacters="&lt;,&gt;,%,&amp;,\,?" />
</system.web>
<appSettings>
    <add key="aspnet:UseTaskFriendlySynchronizationContext" value="true" />
</appSettings>

Мы будем благодарны за любые рекомендации о том, как это исправить.