Not sure if this is a bug or a feature gap - in Archi I've got documentation and/or properties at the folder level (not the view diagram) and when generating an HTML report it is not possible to select the folder in the tree view to show the doc/prop. As these are links they just expand out the folder. I'd expect that the bottom-left pane 'Select an element in the model tree...' would show the doc/prop tabs with the details but this is not the case.
Let me know if you want me to raise a bug or feature request on GitHub.
Thanks
Selecting a folder in the HTML Report tree is not possible so, as you say, you cannot view its Documentation or Properties. I'm not sure if implementing this would affect the expand action of the tree node.
Please open an issue (feature request) so it can be tracked.
I'm not sure if and when this issue will be addressed in this version of the HTML Report, or if it might be part of an updated and improved HTML Report in the future.