I have inserted a stacked balloon in a drawing.  The bottom balloon needs to be set to "text" to reflect an item that should be there but is not visible because it is elsewhere in the view.  To add the second balloon to the stack, I tried selecting the same item twice and also selecting two different items.  Until a few days ago, both balloons remained the same color, black.  Today, I noticed that the "text" balloon has changed to red.

Some information: both balloons are on the same layer, linked to the same drawing view, use the same display state, and use the same configuration.

The second balloon in the stack remains black until I change it to "text" -- then it turns red.  Even without changing the number.  Other stacked balloons, in other drawing views, on other sheets, that have been changed to "text", remain black.  Other non-stacked balloons, set to "text",  on this sheet, remain black.

What would cause this?  What may have I inadvertently changed in my settings for this to occur?