First check that this is truely the case. Views like the Tablebox only show the distinct rows, but they may still exist as two separate rows.
Having checked that, then I suspect that is due to the way the distinct keyword works in QV. If you have any load step for the table (including joins), then the distinct attribute is applied to the table from that point onward. You are dropping the field that is keeping the records distinct. Since they are no longer distinct and the table has the distinct attribute (because an earlier LOAD had the distinct keyword), the "duplicate" row will be dropped.
This applies even on a join, so
Left Join (Table1)
LOAD distinct * Resident Table2;
then Table1 will be marked as distinct and duplicate records will be dropped.
See here:
DISTINCT can be deceiving - The Qlik Fix! The Qlik Fix!
Logic will get you from a to b. Imagination will take you everywhere. - A Einstein
