What Grafana version and what operating system are you using?
9.5.1 , on ubuntu
What are you trying to achieve?
I have 2 datasources, 1 is prometheus, 2 is postgres
I want to use expressiont o add 2 queries to show as 1 single metric
using time series chart.
How are you trying to achieve it?
I created a query from prometheus
and another query from postgres, both can be shown correctly independently.
Then I use expression to add them up
but the new series is empty (while the original 2 raw queries are valid)