I can click on the words 'This PC', 'File Collections', or 'Libraries' in the folder tree and they will expand, but I need to click on the > symbol next to 'Favorites' for it to do likewise, not the word itself. Is this by design?
It's because you can't navigate to the Favorites folder itself. Clicking on it doesn't do anything at all really.
The other folders are all ones you can navigate to, and see their child items in the file display which is next to the tree.
You can also double-click it to expand it.
Ah, yes, I see. Thank you both for replying.