Hello. I am new to Animation and just purchased CTA 4. I am currently on the first project: Getting Started: My First Animation Project. The place I am having trouble with is the Leaf motion 01 in the TimeLIne. It shows in the video tutorial to select Motion on the timeline and delete the extra timeline frames. He then selects  Loop and extends the motion 01 timeline out several frames. 
My problem is that I can't extend the Motion 01 timeline adding more frames. I can only see a little plus at the end of the motion 01 timeline which adds the same timeline again with a brake line (causing to start over with the new motion 01 timeline).
How do I extend a Motion on the timeline?
I hope this all makes since.

iMac 27" I5 3.1 GHz 6 Core 32G 2667 MHz DDR 4 MacOS 10.15 CTA 4 Pipeline XP-Pen Artist 24 Pro