Unsure why this is the case - but the sidebar functionality with respect to manipulating notebooks seems to be very limited
Eg - I cannot generate a new notebook within a stack from within the side bar - instead I have to manually go into notebooks and drag my new notebook into its appropriate stack
Eg - I cannot delete a notebook by right clicking the notebook in the sidebar
Eg - I cannot rename a notebook by right clicking the notebook in the sidebar
Not sure if any one else finds this troublesome or whether others have requested this - but it would make a significant improvement in workflow
Hope EN will consider this improvement