OK. In this case I think you can make it without the tied hash.
You will have to sort the output in printhash (as you did)
to get them in descending order.
si_lence

%hash = (
          '1-1' => 80,
          '1-4' => 26,
          '4-4' => 3,
          '2-2' => 180,
          '2-4' => 72,
          '1-2' => 2196
        );
  $N =2;
  %hash = seq_score($N,%hash);
  printhash(%hash);

#---sub-----
sub seq_score{

  my %spair;
  ($N,%spair) = @_;
  my %topN_pair = ();
  my %seq =();
  
    my $count=1;
    foreach my $key (sort{$spair{$b}<=>$spair{$a}} keys %spair )
    {
        $topN_pair{$key}=$spair{$key};
        last if $count++ >= $N;
    }        
    
   return %topN_pair;
}

sub printhash
{
    my %hash = @_;

    foreach my $key (sort{$hash{$b}<=>$hash{$a}} keys %hash )
    { 
        print $key, ":", $hash{$key}, "\n"
    }
}
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