You open the forecast editor using a Report Definition and select to enter Units and Values. You edit an item, setting both units and value, and save. After refreshing the report the units are saved, but the values are not.
When using a Report Definition, all except the first changed row (for each file, if multiple files) is ignored.
Workaround: If possible avoid entering multiple datatypes with a report definition. It may well be possible to create the desired output using Item Selections instead of a Report Definition.