[SwiftUI][DragDrop][iPadOS] Drop into TabView Sidebar Tab not triggering. How to debug?

Are there tools to inspect why a drag-and-drop drop is not triggering in a SwiftUI app?

I've declared .draggable on the dragging view, and .dropDestination on the receiving TabContent Tab view.

This combination of modifiers is working on a smaller demo app that I have, but not on my more complex one.

Is there a means to debug this in SwiftUI? I'd like to see if the drag-and-drop pasteboard actually has what I think it should have on it.

Notably: "TabContent" has a far more restricted list of modifiers that can be used on it.

[SwiftUI][DragDrop][iPadOS] Drop into TabView Sidebar Tab not triggering. How to debug?
 
 
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