Seems like the problem is the search radius is too large so we are picking up too many stops and only the first stop is highlighted, which might not be the one expected/closest to the mouse.
The problem was actually that on selecting a stop time, rather than simply selecting the currently hovered stop, we were doing the hover calculation again, but obviously wrong.
Seems like the problem is the search radius is too large so we are picking up too many stops and only the first stop is highlighted, which might not be the one expected/closest to the mouse.