Unable to view data by orgunit group set

Hello dhis2 community,

I tried to view data by orgunit group set, unfortunately nothing I could see. However, if I viewed by orgunits which are the same orgunits I assigned to orgunit groups and group set, I could see the data (please have a look at below screenshots).

Could anyone assist what is the reason of unable to view data by orgunit group set? I am using 2.28, build version: eaea7eb, build date: 2017-12-01 06:22.

Thanks,

Rady