Shape.UniqueID(visGetOrMakeGUIDWithUndo) making Undo/Redo unreliable

[Visisthebest]

While debugging a Visio VSTO add-in, I stumbled on to the following issue.

I don't know what Visio is doing internally when I use Shape.UniqueID(visGetOrMakeGUIDWithUndo), but clearly understanding this better is needed.

When defining Undo scopes, Visio Undo/Redo executes exactly as expected when I use Shape.UniqueID(visGetOrMakeGUID) within the Undo scope to add a GUID to a new shape on the page.

But when I change it to: Shape.UniqueID(visGetOrMakeGUIDWithUndo), Undo/Redo starts executing unreliably and I even get 'ghost shapes', meaning a Redo suddenly creates two shapes even though the original transaction created only one.

Obviously I need a better understanding of what happens when Shape.UniqueID(visGetOrMakeGUIDWithUndo) is used, hopefully someone has more insight into this. Thank you!

[Visisthebest]

Please disregard this post for now, this issue is likely this behavior is related to other factors (as well).