Why does vertical spacing reset to 0.00 pt?

[Luke Terheyden]

So I enter:
* Item 1
* Item 2

I select Item 1 and Item 2, and under "List," I set all 3 vertical spacing
options to 2.00 pt.

I want to enter:
* Item 1
* Item 2
* Sub-item 1

As soon as I indent to enter Sub-item 1, the vertical spacing resets to 0.00
pt.