Grouping/ungrouping collapses layers

I think I did something unintentionally awhile back so that now every time I group or ungroup objects on a layer, the layer they are in collapses.  For the life of me, I can't find anything on what keystroke I may have done (if it was a keystroke)  that resulted in this happening.  It's not a critical thing, other than being annoying.

Any help appreciated. Thanks.