Not sure about the issue, it worked well for me. I will check.
Regarding the ...

Not sure about the issue, it worked well for me. I will check.

Regarding the same UI, I think there are some limitations in terms of Form API support. In Drupal 8 version we used the render element Table. But we don't have that in Drupal 7. Hence I used the tableselect Form element. I am open to hearing ideas on how we could achieve the same UI in D7 using Form API.