Stat Panel background color when value is NULL

Hi there.

I am using grafana 6.6.2 to query loki logs as a prometheus data source. (logql)

When I receive no values (null) from a query, the stat panel displays the correct value (in this case DOWN) but the background color remains the last one… doesn’t change. Even placing the base color as red it stays as green (which is the color if i have a value greater that one).

I saw several queries around this topic. Is it something that it is because the stat panel is in beta panel?