I try to use SfPicker control in Windows 10 1809 project, but after adding any item on click or load or basically any event - control lose track of SelectedItem which is always null and SelectedIndex which is always -1.
I've managed to reproduce issue on totally empty project (attachment).
When you click 'OK' after just launching this app everything will work fine, but after clicking on 'Add' and adding item to the list SelectedIndex/Item will always be -1/null.