It is debatable if this is a bug or not, but up to you to decide:
  • Clicking a list: the entire button is clickable when you hover and opens the list. Clear!
  • Clicking a folder: clicking the text opens the folder, clicking the button collapes the folder. I do not expect this so it is very annoying. I prefer to have the folder expand/collapse only.
  • Clicking a space: clicking the text opens the space ánd collapses it. Clicking the button only collapses/expands it. I prefer to use the icon instead.
So I rated this 'bug' for the inconsistencies, and it is probably a feature request for the difference between clicking the button vs. text. Thanks for reading!