[Grafana 7.2.0] Variable of type Query: query never executed against the data source


I’m using Grafana 7.2.0. I created a variable of type “Query”. I selected my custom data source from the dropdown.

Unlike the Grafana version 7.4.2 (which seems to have a bug, as explained here), I am actually able to see the Query field.

However, the query seems to never be executed against the data source. Also, I don’t see any errors. Basically nothing happens (when I type into the query field or tab out of it).

It’s the same when I save the dashboard, refresh the page and look at the dashboard - no query attempts are being made. This is true even when graphs are present (graphs do actually make query requests).

Question: What am I doing wrong? Is there something special that I need to implement with my data source plugin? Could you point me to documentation?