Combo chart error, shows up blank

[GioINI]

Hello,

I have the following table and want to turn it into a combo chart:

But for some reason the chart is totally blank:

It works fine with a bar chart or line chart:

I have set the OK, Early and Late to stacked bars, and the OTD% to a line. Even if I remove the OTD% and use the Combo Chart as a bar chart it still shows up blank, same with only using dimension YearMonth and OTD% as line.

What could be the issue?

Regards,

Andreas