I am having an issue with the charts and dates disappearing.

In the image below you can see bar charts. They are set to be on a rolling 13 month display, using the relative filter to include the last 13 months of data. When the data set is unfiltered, all the months are shown. But when I filter by customer, months when that customer has no activity are removed from the chart.

I have a date query that is used on the x axis of this report, and it is set to 'lookup' the data in a related table where the customer info is

How can I fix this?

Thanks