How does the no data alert work?

For example. I’m using a 1h downsample on data and then alerting on that. If I alert on no data will I be alerted only if there is no data for the entirety of that hour or will I get a notification whenever there is no data retrieved? Do alerts work on downsampled data or do they use the original data queried?

Another note, is there a way to specify the time I want the alert to evaluate for before sending a no data alert? Say for 2h rather than 1h?

I also because I’m looking at the alert history on a graph and it doesn’t seem to be working how I would expect (which is that it alerts on post-downsampled data)

So you can see in the graph that the data never goes above the 1100 point. Now maybe the non-downsampled data does but with how I thought the alert was working I assumed it was alerting on the downsampled data which means it shouldn’t have gone into an ok state until an hour later?