Update row for multiple rows with the same key value

[VVar]

What I'm trying to do is having one excel as an archive and other "live" data sheet when column "AddToArchive" is with value "yes" export the rows to the archive excel file and update the rows with blank values. Exporting works fine but the row update step stops at the first row. How can I solve this problem ? 
Am i using the key column and key values incorrectly ?

[VVar · Accepted solution]

Found the problem. Leaving string('') to make a blank cell on KeyColumn makes the "Update a row" update the same cell over and over again.