All the controls suddenly turned to ControlType.Pane

My application is using Microsoft UI Automation to build a tree that shows the different controls, their name and values. This works fine. However every so often something happens, not able to pinpoint why, but all the controls are of type ControlType.Pane. When I use Inspect they show their real types (e.g. ControlType.Button or ControlType.Edit), but through my app all the controls return type as ControlType.Pane. Even the localize control type name is Pane. 

Why is this happening? Not sure if this is an MS UIA bug or something that I am doing? Please help.