Grouping changes order of layers

Grouping or ungrouping controls changes the layering order of the controls, which is unfortunate! I cannot recall if I observe this behavior consistently, but it is not uncommon for me to experience the following:

I group together a group box and a number of controls I placed inside of it. I then ungroup it to edit one of the controls, but POOF, the group box is now on top of all the controls it was once under, and I must 1st send the group box 'back' a few layers before I can edit what I want.

I'm on Balsamiq Mockups for Desktop version 1.6.25.