Why Change Request screen fails to pop up after saving a modified query?

We created change request for the 1st time for queries of a cube in Transport Connection by dragging over the cube to the right frame and grouping by "In Data Flow Afterwards" and checked the query elements, and then to click the truck picture icon without BEx to generate the change request.

Now for a query for this cube, we can see this query is included in a change request in Transport Connection, however when we modify this query and save it, the change request screen which should lists the change request fails to pop up, why?

Thanks