Wpf - Remove The MsgBox The Code Fails To Run ?

I have a code that uses WPF Interoperability where I have WPF Item that is being added as user control in windows forms. I use the WPF for 3D view where I add a sphere dynamically and it works fine, all I do is just send x, y and radius from the form to WPF and it draws the sphere.

Now here it is the problem I made a loop that reads list of coords and draws them in WPF control, it works perfectly if I add a blank MsgBox but if I remove the MsgBox it only shows the last sphere in the list, Eg For Each obj As Sphere in LstSpheres. MsgBox("") 'If I remove this the code doesn't work. CreateSphere(obj.x, obj.y, obj.radius, Brushes.Red) 'This Sub adds the Sphere in WPF Control Next

How is that possible, and how can it be fixed?

UPDATE:

CreateSphere

CODE: