jps wrote:S2 has always worked the same way - a line highlight will only be displayed in the gutter when the selection is non-empty. You may want to change the selection colour to make them easier to spot.
Was it maybe a bug then? I am positive I was getting line highlights during selection in 2058 which I was just using a few days ago. Maybe not when the selection spanned multiple lines, but I clearly remember using ctrl+d and find all on a word and scrolling through a file fast and using the line highlights to find the selections.