Parameter inside folder under multiparm doesn't get correct index when the folder is inserted

[teddy8193]

When the parameter structure is like this, the parameter inside the folder doesn't get correct index when it's inserted.

Multiparm Block(List)
+-Label (This label parameter is here to enable "+-" insert button.)
    Folder
        Parameter (Index on this parameter is bugged)

For example, there is a HDA like this

folder_multiparm (Multiparm Block)
+-testLable_1 (Label parm)
    testFolder (Folder)
        testParameterA_1
    testParameterB_1

In the example above, testParameterA_1 is inside the testFolder, and testParameterB_1 is directly placed under the folder_multiparm.
The reason why the folder doesn't have index is because I can't see it in UE4.

When I insert by clicking the "+-" button, it becomes like this.
folder_multiparm (Multiparm Block)
+-testLable_1 (Label parm)
     testFolder (Folder)
        testParameterA_1
    testParameterB_1
+-testLable_2 (Label parm)
    testFolder (Folder)
        testParameterA_1        <--Bugged!!
    testParameterB_2

The testLable and testParameterB gets updated index, but the testParameterA doesn't.

Thanks,