FCP 10.6.8 - Clip moved down in timeline with new blank rows above, and now are volatile

I'm not sure what I did, but the video clip jumped down and new blank rows are between it and its Caption entries. And if I click the clip to select it, it is automatically trimmed from the start to where I click. (A red line shows where it will trim to.)

I can select the clip with the Edit menu and Select Clip, but looking in the Mark menu, Unrate is grayed out, so I guess I didn't accidentally Reject the clip.

Can anyone say what this is from the image here? The gray handle-like block on the start of the timeline in the blank row above doesn't seem to do anything, but I think it popped in when I accidentally did something and the clip dropped so low in the timeline and became prone to instant trimming.

?? -- Thx