Can't drag select verticaly in column while scrolling or reach the edge.

1. Can't drag select multiple files in column while scrolling.
2. With drag select multiple files in column to bottom edge quite slow. And after reach the end point, it appears multiple unstable issues:
- sometimes it lost selection after drag select and scroll,
- sometimes it returns back first page, only selects the files on first page.
- sometimes it didn't scroll at all, only stay at first page.