Graph shows "No data point" when multiple sources are selected


My Grafana (v5.1.3 (087143285)) has two data sources; Zabbix and its Postgres DB.
I’ve created a graph that shows data coming from multiple hosts and added a function to display only top 5
results. When this setting is configured I get a “No data points” message in the graph with no data, It looks
as follows:

Needless to say that among the /.*/ hosts under the AWT group, there are hundreds of hosts that have data on the item that I am collecting. Here is the same exact screen but pointing at one machine only:

It’s important to note that some machines inside this group might not have any data coming from this item.
If I am not missing something here than it seems like a bug to me. Any help would be highly appreciated! :slight_smile: