I meant something like this:

use strict;
use warnings;
use Data::Dump qw/pp dd/;
use List::Util qw/min/;



sub pw_not_ok {
    my $pw  = shift;

    my $short     =
      sub { "is too short" };

    my $lowercase =
      sub { /[a-z]/ ? "" : "has no lowercase character" };

    my $uppercase =
      sub { /[A-Z]/ ? "" : "has no uppercase character" };  ### FIXED

    my $number =
      sub { /[0-9]/ ? "" : "has no number" };

    my $special =
      sub {
          if (
              /[\x21-\x2F]/ ||
              /[\x3A-\x40]/ ||
              /[\x5B-\x60]/ ||
              /[\x7B-\x7E]/
             ) {
              return "";
          } else {
              return "has no special characters";
          }
      };

    my $pass = sub {""};



    my @rules_for_class =
      (
       [ $short ],
       [ $short ],
       [ $lowercase, $uppercase, $number ,$special ],
       [ $lowercase, $uppercase, $number           ],
       [ $lowercase, $uppercase                    ],
       [ $pass ]
      );

    my $len = length $pw;

    my $idx = min(int($len/4),5);

    for my $rule ( @{ $rules_for_class[$idx] } ) {
        $_ = $pw;
        if ( my $err = $rule->() ) {
            return $err;
        }
    }
    return;
}

# --------- Tests

for my $pw (
            "A" x 3 ,
            "A" x 7 ,
            "A" x 11,
            "a" x 5 . "A" x 3,
            "a" x 5 . "A" x 3 . "1",
            "a" x 5 . "A" x 3 . "1" .":",
            "a" x 24,
           ){
    if ( my $err = pw_not_ok($pw) ){
        warn "ERROR: $pw is $err\n";
    } else {
        print "OK: $pw\n"
    }
}
[download]

    
ERROR: AAA is is too short
ERROR: AAAAAAA is is too short
ERROR: AAAAAAAAAAA is has no lowercase character
ERROR: aaaaaAAA is has no number
ERROR: aaaaaAAA1 is has no special characters
OK: aaaaaAAA1:
OK: aaaaaaaaaaaaaaaaaaaaaaaa
[download]

UPDATE

see Re^6: Efficient way to verify scalar contents