Adding to this as I ran into similar
Only an issue with Widgets other BP you can open and reparent without an issue but for some reason a Widget will not open, there is no Reparent option on the context menu, I am really not seeing a way save the widget which is highly unfortunate
Class names do change Epic, if your going to hard bind to a name, fine, but make sure there is a way to manually rebind as you did with Actor derived BP but Widget BP seems to just be a dead stick