How odd. Try this SSCCE which works fine for me.

#!/usr/bin/env perl 
use strict;
use warnings;
use File::Copy 'move';

my $indir = '/tmp/foo';
my $outdir = '/tmp/bar';
mkdir $indir;
mkdir $outdir;
for my $f (qw/a b c/) {
    open my $out, '>', "$indir/$f" or die "Opening $f: $!";
    print $out 'Woo-hoo!';
    close $out;
}

opendir my $dir, $indir or die "Bad Dir $indir: $!";
while (my $infile = readdir ($dir)) {
    if ($infile =~ /b/) {
        print "Moving '$infile' ...\n";
        move ("$indir/$infile", $outdir)
            or die "move failed: $! moving $indir/$infile to $outdir" 
+.
                " while we are in $ENV{PWD}\n";
    } else {
        print "Skipping '$infile' ...\n";
    }
}
[download]

Thank you very much!!.It worked.