Action 'Add Item(s) to change' from relationship grid creating multiple items in version 10 and 11

Hi,

In version 10, if we run the action 'Add Item(s) to change' from relationship grid after selecting multiple items then we see the popup multiple times and for each selected item a change item is being added separately. The same happening in 11 also.

Which was working fine in version 9.3 as it was creating one change item and adding all the selected items to same item. 

How to solve this problem in version 10?

Or is there a way to get the selected items' id from relationship grid? Like how we get the ids of selected items from main grid using:

var grid = top.main.work.grid;

var selids = grid.GetSelectedItemIDs(",");

Please help me. Thank you, Ransok