How to hide/unhide feeds and folders with no unread articles from left navigation bar?
Click on the three dots next to "Following" in the left sidebar. This action will open a modal window. Within the modal, go to the "Sites and Folder View Option" section. If you select 'Show Updated', only feeds and folders containing unread articles will be displayed in the left sidebar. Alternatively, if you choose 'Show All', all feeds and folders will be visible, regardless of their unread status.