I'm making a slideshow by attaching still drawings together. When I drag a frame to extend the timeline, it snaps back as soon as I release it. The preview then stops whenever it reaches this point.
https://drive.google.com/open?id=1sEi3sW3zp6rwBJDMBSmSVSW26cyTcLOa
Subject line edited by moderator to make it clearer.

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