I have the outline and note up top, backlinks and tags in a lower pane. So try testing with them all in one pane? See screenshot.

I saved this as a new workspace and tried switching around to other workspaces and restarting Obsidian a few times. So far the note has stayed put. 
Edit to add that I saved a few variations with the note being displayed in the saved workspace and others with the outline pane displayed. I also have one with all the views (outline, tags, backlinks, my note) in one pane, one with these split up. So I guess I’ll see if any of them lose the note in the future!