some Graphs not showing values when period is 4 days or more

[username_taken]

I have a bunch of graphs for items that when I extend the graph period to 4 or more days the value goes right down to zero. If I go through monitor-latest data I see what looks like the actual value in a light yellow and then what looks like a bad calculation of average. see screenshot.

How can I fix this so that the graph shows actual values ?

[username_taken]

doing some more digging it seems to be a difference between 'history' and 'trends'. but I'm still not sure how to force it to show the more accurate number.