Login to https://test.idempiere.org/webui
go to open orders report
click on report customization
choose Date Ordered and Doc status in the order by criteria. Having Date ordered as first in the list and then Doc status
close the wizard and see that date ordered and doc status would have sort no. as 10 and 20 in Print format
Again open the report customization and go to sort criteria and move the doc status to up and date ordered would become 2nd. Now check in print format, that date ordered would have sort no. as 0.
Having 0 as sort no. means do not sort by this column
Potential cause of the issue is in WRC3SortCriteriaPanel.java#migrateValueWithinYesList (Event event)