Sometimes when I add older points on the graph they do not show up. Is there a limit to the number of days back you can go on annotations?
As far as I know, no... but the "Applied Date" of the annotation must be within the Data Range of the Line Graph in order to show...
For instance, If my graph is showing last 30 days, I wouldn't see an annotation from 60 days ago... but if I change my panel to show the time frame where that annotation is, I should see it....
I found this note in the annotation but don't understand what it means (10 max)?
You can add up to 10 metrics on this date to annotate.
So in your screenshot, it's cut off before the first metric (which should be whatever you started the "Create Annotation" from), but you can add additional metrics here:


I guess if you are annotating some issue or spike it data, you can indicate which metrics were most impacted?
That's the odd thing. I'm adding the annotation directly to the graph by right clicking and go through the process like I did on others, but it just doesn't want to show up.