There must be something else the issue here, as if you remove all of the trailing tabs from the string, it works fine on all versions of perl I have installed currently.

Works:

use warnings;
use strict;

my $value = "A\tB\tC\tD\tE\tF";
my @flds = split(/\t/, $value);

$flds[16] = undef;
$flds[8] = 0;

print scalar @flds;

__END__

17
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Broken:

use warnings;
use strict;

my $value = "A\tB\tC\tD\tE\tF\t\t\t\t\t\t";
my @flds = split(/\t/, $value);

$flds[16] = undef;
$flds[8] = 0;
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