What is going on here ?

Maybe the filename has newlines in it?

To be sure instead of merely printing use ddumpering^{Basic debugging checklist} to visualize your data (lesson courtesy of Basic debugging checklist and brian's Guide to Solving Any Perl Problem )

Also, you're not taking free help :) (strict/warnings...Read this if you want to cut your development time in half!

You're using readdir which is like making your own hats pimperator, use find/rule

#!/usr/bin/perl --
use strict; use warnings;
use Data::Dump qw/ dd /;
use Path::Tiny qw/ path cwd /;
use File::Find::Rule qw/ find rule /;
my @names = find( directory => maxdepth => 1, in => $top.$second );
my @files = find( file => name => qr/\.txt$/i, in => \@names );
for my $fp ( @files ){
    my $name = path( $fp )->basename;
    dd( $fp, $name );
}
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update: a test :) simpler find/rule usage, mindepth means start testing rules at this depth

#!/usr/bin/perl --
use strict; use warnings;
use Data::Dump qw/ dd /;
use File::Find::Rule qw/ find rule /;
my $startdir =  'file-find-rule-mindepth-maxdepth';
my @files = find(
    file     => name => qr/\.txt$/i,
    mindepth => 2,
    maxdepth => 2,
    in       => $startdir,
);
dd( \@files );

__END__
$ findrule file-find-rule-mindepth-maxdepth
file-find-rule-mindepth-maxdepth
file-find-rule-mindepth-maxdepth/6.txt
file-find-rule-mindepth-maxdepth/a
file-find-rule-mindepth-maxdepth/q
file-find-rule-mindepth-maxdepth/q/6.txt
file-find-rule-mindepth-maxdepth/q/r
file-find-rule-mindepth-maxdepth/q/r/5.txt
file-find-rule-mindepth-maxdepth/q/s
file-find-rule-mindepth-maxdepth/q/s/7.txt
file-find-rule-mindepth-maxdepth/x

$ perl file-find-rule-pimperator.pl
["file-find-rule-mindepth-maxdepth/q/6.txt"]
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