Missing Inspector scrollbar until re-select clip

Start on Edit page with a clip selected (in my case, I had a stack of 2 clips; the upper clip is selected and has an alpha key from the Color page). The inspector is visible and I can scrollbar up/down to see the Stabilize section and the Transform section. Click to Color page. If Key tab is selected, I click Power Window tab; or vice-versa. Click back to Edit page. While the same clip still appears selected in the timeline - the scrollbar is gone from the Inspector, and the Stabilize section is missing (by contrast, retime and scaling are still there). If I click another clip and click back to the desired clip, then the scrollbar is visible again.