No I did not have warnings on.

my $pattern  = '\\Aaudit';
my $no_file_error      ="TRUE";
my @dir_files =  $ftp->dir($ftp_directory);
$Data::Dumper::Useqq=1;
print Dumper($pattern);
my $netrc = Net::Netrc->lookup($ftp_server) or die ("Could not find lo
+gin info in .netrc for $ftp_server");

     my $ftp = Net::FTP->new($ftp_server, Port => $ftp_server_port, De
+bug => 1) or die ('Could not create ftp object');

     $ftp->login($netrc->login, $netrc->password) or die ('Could not l
+og in'), $ftp->message;

     $ftp->binary();

    #print directory of files before command
     print "--------------------First List all files------------------
+\n";
     my @dir_files =  $ftp->dir($ftp_directory);
     foreach my $list(@dir_files){
       print "$list\n";
     }

    @dir_files = grep { $_ =~ /$pattern/ } @dir_files;
     if (@dir_files == 0) {
      if ($no_file_error eq "TRUE") {
        print "No files exist with that $pattern\n";
      } else {
        print "Send Email: Cannot find files to GET for parameter $pat
+tern";
      }} else {

     for my $list(@dir_files){
       print "$ftp_command $list\n";
     }
     }
[download]

I added data::dumper and warnings Output with audit

$VAR1 = "audit";
Net::FTP>>> Net::FTP(2.77)
Net::FTP>>>   Exporter(5.63)
Net::FTP>>>   Net::Cmd(2.29)
Net::FTP>>>   IO::Socket::INET(1.31)
Net::FTP>>>     IO::Socket(1.31)
Net::FTP>>>       IO::Handle(1.28)
Net::FTP=GLOB(0xaec9e8)<<< 220 Titan FTP Server 11.20.2264 Ready.
Net::FTP=GLOB(0xaec9e8)>>> USER xupromgr
Net::FTP=GLOB(0xaec9e8)<<< 331 User name okay, need password.
Net::FTP=GLOB(0xaec9e8)>>> PASS ....
Net::FTP=GLOB(0xaec9e8)<<< 230-Welcome xupromgr from 10.253.2.119. You
+ are now logged in to the server.
Net::FTP=GLOB(0xaec9e8)<<< 230 User logged in, proceed.
Net::FTP=GLOB(0xaec9e8)>>> TYPE I
Net::FTP=GLOB(0xaec9e8)<<< 200 Type set to I.
--------------------First List all files------------------
Net::FTP=GLOB(0xaec9e8)>>> PASV
Net::FTP=GLOB(0xaec9e8)<<< 227 Entering Passive Mode (10,253,1,56,236,
+13).
Net::FTP=GLOB(0xaec9e8)>>> LIST /AS/testftp
Net::FTP=GLOB(0xaec9e8)<<< 150 File status okay; about to open data co
+nnection.
Net::FTP=GLOB(0xaec9e8)<<< 226 Closing data connection. Transferred 41
+5 bytes.
drw-rw---- 1 xupromgr xupromgr          512 Mar 29 08:04 .
drw-rw---- 1 xupromgr xupromgr          512 Mar 28 13:54 ..
-rw-rw---- 1 xupromgr xupromgr           18 Feb 27 14:21 no_audit.txt
-rw-rw---- 1 xupromgr xupromgr           18 Feb 27 14:21 no_audit_date
+.txt
-rw-rw---- 1 xupromgr xupromgr           10 Feb 27 14:08 auditsample.t
+xt
-rw-rw---- 1 xupromgr xupromgr           11 Feb 27 14:21 audit_date.tx
+t
get -rw-rw---- 1 xupromgr xupromgr           18 Feb 27 14:21 no_audit.
+txt
get -rw-rw---- 1 xupromgr xupromgr           18 Feb 27 14:21 no_audit_
+date.txt
get -rw-rw---- 1 xupromgr xupromgr           10 Feb 27 14:08 auditsamp
+le.txt
get -rw-rw---- 1 xupromgr xupromgr           11 Feb 27 14:21 audit_dat
+e.txt
[download]

This list is what is outputted with ^audit

$VAR1 = "^audit";
Net::FTP>>> Net::FTP(2.77)
Net::FTP>>>   Exporter(5.63)
Net::FTP>>>   Net::Cmd(2.29)
Net::FTP>>>   IO::Socket::INET(1.31)
Net::FTP>>>     IO::Socket(1.31)
Net::FTP>>>       IO::Handle(1.28)
Net::FTP=GLOB(0x1cdf9e8)<<< 220 Titan FTP Server 11.20.2264 Ready.
Net::FTP=GLOB(0x1cdf9e8)>>> USER xupromgr
Net::FTP=GLOB(0x1cdf9e8)<<< 331 User name okay, need password.
Net::FTP=GLOB(0x1cdf9e8)>>> PASS ....
Net::FTP=GLOB(0x1cdf9e8)<<< 230-Welcome xupromgr from 10.253.2.119. Yo
+u are now logged in to the server.
Net::FTP=GLOB(0x1cdf9e8)<<< 230 User logged in, proceed.
Net::FTP=GLOB(0x1cdf9e8)>>> TYPE I
Net::FTP=GLOB(0x1cdf9e8)<<< 200 Type set to I.
--------------------First List all files------------------
Net::FTP=GLOB(0x1cdf9e8)>>> PASV
Net::FTP=GLOB(0x1cdf9e8)<<< 227 Entering Passive Mode (10,253,1,56,235
+,244).
Net::FTP=GLOB(0x1cdf9e8)>>> LIST /AS/testftp
Net::FTP=GLOB(0x1cdf9e8)<<< 150 File status okay; about to open data c
+onnection.
Net::FTP=GLOB(0x1cdf9e8)<<< 226 Closing data connection. Transferred 4
+15 bytes.
drw-rw---- 1 xupromgr xupromgr          512 Mar 29 08:04 .
drw-rw---- 1 xupromgr xupromgr          512 Mar 28 13:54 ..
-rw-rw---- 1 xupromgr xupromgr           18 Feb 27 14:21 no_audit.txt
-rw-rw---- 1 xupromgr xupromgr           18 Feb 27 14:21 no_audit_date
+.txt
-rw-rw---- 1 xupromgr xupromgr           10 Feb 27 14:08 auditsample.t
+xt
-rw-rw---- 1 xupromgr xupromgr           11 Feb 27 14:21 audit_date.tx
+t
No files exist with that ^audit
[download]

This is with the variable set to \\Aaudit

$VAR1 = "\\Aaudit";
Net::FTP>>> Net::FTP(2.77)
Net::FTP>>>   Exporter(5.63)
Net::FTP>>>   Net::Cmd(2.29)
Net::FTP>>>   IO::Socket::INET(1.31)
Net::FTP>>>     IO::Socket(1.31)
Net::FTP>>>       IO::Handle(1.28)
Net::FTP=GLOB(0x18539e8)<<< 220 Titan FTP Server 11.20.2264 Ready.
Net::FTP=GLOB(0x18539e8)>>> USER xupromgr
Net::FTP=GLOB(0x18539e8)<<< 331 User name okay, need password.
Net::FTP=GLOB(0x18539e8)>>> PASS ....
Net::FTP=GLOB(0x18539e8)<<< 230-Welcome xupromgr from 10.253.2.119. Yo
+u are now logged in to the server.
Net::FTP=GLOB(0x18539e8)<<< 230 User logged in, proceed.
Net::FTP=GLOB(0x18539e8)>>> TYPE I
Net::FTP=GLOB(0x18539e8)<<< 200 Type set to I.
--------------------First List all files------------------
Net::FTP=GLOB(0x18539e8)>>> PASV
Net::FTP=GLOB(0x18539e8)<<< 227 Entering Passive Mode (10,253,1,56,236
+,32).
Net::FTP=GLOB(0x18539e8)>>> LIST /AS/testftp
Net::FTP=GLOB(0x18539e8)<<< 150 File status okay; about to open data c
+onnection.
Net::FTP=GLOB(0x18539e8)<<< 226 Closing data connection. Transferred 4
+15 bytes.
drw-rw---- 1 xupromgr xupromgr          512 Mar 29 08:04 .
drw-rw---- 1 xupromgr xupromgr          512 Mar 28 13:54 ..
-rw-rw---- 1 xupromgr xupromgr           18 Feb 27 14:21 no_audit.txt
-rw-rw---- 1 xupromgr xupromgr           18 Feb 27 14:21 no_audit_date
+.txt
-rw-rw---- 1 xupromgr xupromgr           10 Feb 27 14:08 auditsample.t
+xt
-rw-rw---- 1 xupromgr xupromgr           11 Feb 27 14:21 audit_date.tx
+t
No files exist with that \Aaudit
[download]