Clustered column chart zero/0 value

Hi,

I have a clustered column chart with 2 values displayed - forecast and actual. When both values exist they display fine, but when one value does not exist neither value shows. So this a forecast vs spend so sometimes you have forecast a value but there is no value currently in actual. Or sometimes an actual value may exist when nothing had been forecasted. But when either of these scenarios happen, the visual doesn't display a single column for the value that does exist.

So how can I get a value to display if the other is null?