Expand Appearance Issue - Inconsistent

[EDeGuzman]

I've been running into issues with the Expand Appearance and Outline Stroke functions when converting a custom brush into shapes. This issue seems pervasive and the end result typically creates a bounding box around the shape rather than leaving only shape created by the brush. When combining the shapes using the Unite function (Pathfinder>Shape Modes>Unite), you end up with the rectangular bounding boxes rather than the desired shape. This requires you to have to ungroup and remove the bounding box before uniting the final shapes. This can be tedious and time consuming. I've included a sample .gif below demonstrating the issue. Does anyone have suggestions on how to resolve this issue? 

[EDeGuzman]

Just to clarify Fig 1 is the way it should be functioning. Fig 2 is what I've been finding typically is happening.

[Monika Gause]

Which version is it? and which brushes?

In some versions this happened. Illustrator didn't delete the invisible box (are you sure you made the box invisible?)

But I cannot reproduce it in the latest version using art brushes and scatter brushes.