Behavior window disappears

This is actually about Motion 4. For some reason, when I'm looking at the timeline, and add a behavior to a clip, the little drop down window for the behavior has disappeared. I can't adjust the length in the timeline tand see what I'm doing, like when I match the transition time to another effect. I can call it up in the media pane, but don't understand why I now can't see the things that I apply to a clip in the timeline. I can see it in the inspector. And it's not that I have checked to behavior on/off icon in the clip. that doesn't seem to matter.