When adjusting the center point for groups in the Layout tab, the red cross disappears when you increase or decrease the X or Y offset.
You then have to select a different group, then re-select the original group you were trying to change to see where the red cross has moved to.
I'm sure it didn't used to disappear in previous versions, but has since version 19 (or maybe 18). Have just checked version 21 and problem is still there.