I suspect you are reading a file created with \r\n (carriagereturn-linefeed) line endings (e.g., on a Windows system) on a system (e.g., *nix) that uses \n (linefeed) line endings. On the reading system, the line-feed is chomp-ed off leaving the carriage-return. This can be simulated with something like:
Win8 Strawberry 5.8.9.5 (32) Fri 09/03/2021 23:52:22
C:\@Work\Perl\monks
>perl
use strict;
use warnings;
use Data::Dump qw(dd);
my $data = <<"EOD";
AA\r
AAH\r
AAHED\r
AAHING\r
AAHS\r
AAL\r
ZYTHUMS\r
ZYZZYVA\r
ZYZZYVAS\r
ZZZ\r
ZZZS\r
EOD
open my $fh, '<', \$data or die $!;
my @words = <$fh>;
close $fh;
dd \@words;
chomp @words;
dd \@words;
print "@words\n";
^Z
[
"AA\r\n",
"AAH\r\n",
"AAHED\r\n",
"AAHING\r\n",
"AAHS\r\n",
"AAL\r\n",
"ZYTHUMS\r\n",
"ZYZZYVA\r\n",
"ZYZZYVAS\r\n",
"ZZZ\r\n",
"ZZZS\r\n",
]
[
"AA\r",
"AAH\r",
"AAHED\r",
"AAHING\r",
"AAHS\r",
"AAL\r",
"ZYTHUMS\r",
"ZYZZYVA\r",
"ZYZZYVAS\r",
"ZZZ\r",
"ZZZS\r",
]
ZZZSYVAS
Give a man a fish: <%-{-{-{-<