Core problem is too much indirection, which means you are making references back to an original when you probably intend to make copies. I won't dig too deep into this, but I'll show code that illustrates the problem.

This code just makes pointers to a single version of the structure, without making copies of the structure's changes.

#!/usr/bin/perl
use warnings;
use strict;
use Data::Dumper;
my @data=({}); 
    
    my %work_request = (
       "DR"=>[0,0,0,0,0],
       "SAT ITAMS"=>[0,0,0,0,0],
       "PROD ITAMS"=>[0,0,0,0,0]
    );

#push @data, [ %work_request ];
push @data, \%work_request;

$work_request{DR} = [1,2,3,4];

#push @data, [ %work_request ];
push @data, \%work_request;

print Dumper( @data );
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and the output is:

C:\Code>perl how_many_indirects.pl
$VAR1 = {};
$VAR2 = {
          'PROD ITAMS' => [
                            0,
                            0,
                            0,
                            0,
                            0
                          ],
          'SAT ITAMS' => [
                           0,
                           0,
                           0,
                           0,
                           0
                         ],
          'DR' => [
                    1,
                    2,
                    3,
                    4
                  ]
        };
$VAR3 = $VAR2;
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This version of code copies the unique components as the base structure changes.

#!/usr/bin/perl
use warnings;
use strict;
use Data::Dumper;
my @data=({}); 
    
    my %work_request = (
       "DR"=>[0,0,0,0,0],
       "SAT ITAMS"=>[0,0,0,0,0],
       "PROD ITAMS"=>[0,0,0,0,0]
    );

push @data, [ %work_request ];
#push @data, \%work_request;

$work_request{DR} = [1,2,3,4];

push @data, [ %work_request ];
#push @data, \%work_request;

print Dumper( @data );
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and the output is:

C:\Code>perl how_many_indirects.pl
$VAR1 = {};
$VAR2 = [
          'PROD ITAMS',
          [
            0,
            0,
            0,
            0,
            0
          ],
          'SAT ITAMS',
          [
            0,
            0,
            0,
            0,
            0
          ],
          'DR',
          [
            0,
            0,
            0,
            0,
            0
          ]
        ];
$VAR3 = [
          'PROD ITAMS',
          $VAR2->[1],
          'SAT ITAMS',
          $VAR2->[3],
          'DR',
          [
            1,
            2,
            3,
            4
          ]
        ];

C:\Code>
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