WPF MVVM ComboBox SelectedItem or SelectedValue not working

Question

Update

After a bit of investigating. What seems to be the issue is that the SelectedValue/SelectedItem is occurring before the Item source is finis

Answer 1

I have had similar issues and it was solved by making sure I was implementing IEquatable properly. When the binding occurs, it is trying to see if the objects match so make sure you are properly implementing your equality checking.