Great response! I did not notice it when I wrote and tested much the same thing.

use strict;
use warnings;
use Test::Simple tests => 1;
my $multi_line_string
    = "yadda text: 123 yadda yadda\n"
    . " text: 456 yadda\n"
    ;

$multi_line_string =~ /\A .* (text\:\s\d{3}) /xms;

my $expected = 'text: 456';
my $match    = $1;

ok( $match eq $expected, 'Match last occurrence');



OUTPUT:
1..1
ok 1 - Match last occurrence
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