Stab in the dark: XML::Simple? You might look at the ForceArray => 1 option. IIRC that would solve your issue by making them all arrays.

Tangent-

if ( $content->{Addresses}{ArrayOfAddressResponse}{AddressResponse} =~ /ARRAY/ )

-is probably better as something like-

my $item = $content->{Addresses}{ArrayOfAddressResponse}{AddressRespon
+se};
if ( ref($item) eq 'ARRAY' ) ...
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Update: there's also this sort of thing-

my $address_ref = $content->{Addresses}{ArrayOfAddressResponse}{Addres
+sResponse};

my $addresses = ref($address_ref) eq 'HASH' ?
   [ $address_ref ] : $address_ref;
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-which will always give you back an array ref of hashes. Note that it doesn't account for unexpected values, e.g., undef, a scalar, a different type of ref, etc.