The column is constantly popping open and many times we try to close it and it insist on staying open. We hardly use this feature and we are constantly trying to close it.
Would be nice if the black arrow button could have a tighter grip on the column from automatically opening all the time.
The setting to stop the sidebar showing is within the main settings page and the category 'Interface Settings'
If you uncheck 'Expand Expected Arrivals List Automatically' then this will only show when the arrow is selected and not be default.
Hopefully this is the setting you were looking for.