MultiGraph does not show all pens until zoomed

A MultiGraph of 3 pens is only showing 1 pen in the 1-day view. If zoomed inn all 3 pens are drawn.
Here is a video describing the problem and my question: eul-mwa

I suspect you are using phpfina feeds that have a fixed interval that is smaller than the update interval of the source data. for example 60s data being saved to a 10s phpfina feed, this results in 5 out of 6 datapoints being “null”.

When you are looking at the full graph it just so happens that the start time and interval are falling on all the null datapoints for 2 of the traces.

When you zoom in or change the interval you are moving the targeted sample data points and valid data is being found.

Tell us more about the feed types and the data source (including both intervals).