References to Geometry Paths break when dragging group stencil to drawing

[celoranta]

I have a stencil including grouped parent and child shapes. 
The child shape's angle formula is:

GUARD(ANGLEALONGPATH(Sheet.5!Geometry1.Path,Sheet.5!User.Row_17)-90 deg)

"Sheet.5" is the parent shape.

• When I edit the stencil directly, everything works well.
  When I drag a copy to my drawing, this field returns #REF error.
  The text of the formula in the child shape's shapesheet is correct.  (ie The references have changed properly to refer to the new copy of the parent)
  However, the text is in BLACK, not BLUE; suggesting that it is no longer being interpreted as an off-sheet reference.
  If I enter the formula and hit 'enter,' the reference goes blue again.

Is this a known limitation, a new bug, or am I doing something wrong?

Best,

Chris

[Surrogate]

Which Visio version ?

[celoranta]

Office 365 / Visio 2016 Professional