CC 2021 Timeline Missing a Film Segment

[Ezad]

hello

Hello

The beginning of the film there is a clip that shows as a black screen however the other clips in the timeline show in the monitor. It is the green bar as shown in the image. I think the beginning clip will become viewable in the monitor if I can move the green bar to the left. Let me know how to fix this so I can view all the clips. Thanks!