Perhaps you ticked the wrong boxes.
“Tools > Customize… > [Status] > [X] Number of Lines”
Actually reads
Number of Lines (in the selection/total)
So this has nothing to do with bookmarks.
The option to display the number of bookmarked lines in the status bar is.
Tools → Customize… → Status → Bookmark Count in the Entire Document
In version 25.2.0 the status bar then displays.
… | 0/7 lines | 4 Bookmarks
4 Bookmarks actually means “4 bookmarked lines”. Adjacent bookmarked lines are counted individually, i.e. are seen as separate bookmarks.