I reported this issue to the support desk and got a reference number PF-33567. I don't think it is solved. I think they see it as a request and not a bug, which strikes me as odd, because who would want this behavior?
Anyway, you could also use BI-viewer for charts, but the BI-viewer has similar behavior. However, on a different occasion OneStream mentioned this workaround for the BI-viewer:
Drag the amount column to hidden dimensions and apply a filter to the chart as shown.
That filters out the nodata values and shows a clean chart. In this example calculated fields are used as values for the chart, but you get the idea.
