One more clarification:  when I select (for example) descendant
versions in the Feature Relation tool, the button appears pushed in while
the descendants are being calculated.  When the calculation ends and the
descendants of the feature are displayed, the pushed-in button pops out
again and the only thing that distinguishes it from other buttons is a
thin line drawn around it.  So the problem seems to be more that the
button doesn't retain its "pushed-in" appearance.