When a child band has no data row, it disappears when it is collapsed. I think it is a bug.
I'm using 2016.1.
Hello Anakin,
No, this is not a bug. By default, the grid shows expansion indicators on each row of a band with child rows. If any of the rows has no child rows when you try to expand it, it shows nothing. You may control whether to display or not and when to display or not the expansion indicators by setting ExpansionIndicator property. You may find additional information about this property in our online documentation here.
You wrote you are collapsing child band with no data row. Actually, I do not see a way to have such band in the grid. If you have a band with no DataRows in it, this could be an issue. If this is what happens at your side, I will need a sample reproducing this scenario for further investigations.
Please let me know if you have any further questions.
Hello,
The fix for development issue 220779 is available in the latest service release available from the My Keys and Downloads page.