Making Tree - Can Not Move Branch

Using Unity 2019.3.6. Adding Tree using Unity’s 3D Tree Object.
I was able to add a new branch. Then I select the branch. The branch is highlighted, and shows the “nodes” along it (little squares and circle shapes)
I select the Move Branch tool. I can click and drag the nodes all along branch to change branch shape, but if I click on node at base of branch (circle shape) I can not move branch.

Is this a bug in Unity? Is there some trick not explained in Docs?

Yo Unity this problem is still in the latest version. 2020.1.6