The latest Firefox has a bookmark button near the address bar. When the bookmark pane is showing and then Firefox shutdown, the bookmark state is lost. When Firefox restarts the bookmark pane is not visible.
The temporary bookmark view is a problem for my mother. She lost Windows because Microsoft bricked her PC with the Meltdown/Spectre updates. She is learning Linux and a new Browser but she is older and its a little harder for her.
Mozilla has a KB at Use the Firefox sidebar to access bookmarks, history and social features, but it does not discuss how to make the changes permanent.
How do I ensure the Bookmarks pane setting is permanent?