Try running a simplified version of the script and print the responses

#!/usr/bin/env perl
use warnings;
use strict;

my $serverlist  = 'srvlst.txt';
open IN, '<',$serverlist
   or die "Run aborted. Cannot open endpoint list file ($serverlist)";

while (my $HOST = <IN>) {
  chomp $HOST;
  print "Pinging $HOST\n";
  my $PingReply = `PING -n 1 -w 1 $HOST`;
  print "[$PingReply]\n";
  
  if ($PingReply =~ /Reply from/) {
    my @Temp = split / /, $PingReply;
    my $IP = $Temp[2];
    $IP =~ s/\[//g;
    $IP =~ s/\]//g;
    print "IP = [$IP]\n";

    my $NBTResults = `nbtstat -a $IP | find \"UNIQUE\"`;
    print "nbtstat result
    [$NBTResults]\n";
  }
}
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