Load Addin in Excel - Forecfully

I had developed a set of Excel UDFs, which i want to load each time i open my Excel via Interop APIs. Hence, I had forcefully loaded that Addin through the Workbook_Open() Event in VBA

Private Sub Workbook_Open()
    Application.AddIns("sampleAddin").Installed = False
    Application.AddIns("sampleAddin").Installed = True
End Sub

This code is working fine, when I open the work book for the first time and performs all the operations as expected. But when I perform a recalculation operation on the workbook using Ctrl + Alt + F9, the functions created and deployed using the addin are not called. 

I am sure that there is no issue in my addin deployment, but I need some guidance regarding the reloading of the addin when the user performs the recalculation. Pls guide.