One possible bug I see: print {*STDOUT}, "\n";.

In the code I provided earlier in this thread, the $csv->print(....) was directing to STDOUT because I didn't want to set up an output file in an example script. Also, the newline was explicitly output because I noticed that one wasn't being inserted between CSV rows automatically by $csv->print(...).

Now in your solution you've got $csv->print($FILE...), but haven't directed the "print {*STDOUT} "\n"; to $FILE instead.

So you may want to look at the CSV it's outputting and verify that there's a newline being created between what you intend to be CSV rows. It may not be happening.