Deployer always locks on deployment

[sts-ryan-holton]

• Deployer version: 7.0.0-rc.6
• Deployment OS: CentOS 8 Stream

<?php
namespace Deployer;

require 'recipe/laravel.php';
require 'deploy/recipe/sts-npm.php';
require 'deploy/recipe/sts-brand.php';
require 'deploy/recipe/sts-composer.php';

// Project repository
set('repository', 'git@github.com:company/brand-site.git');

// [Optional] Allocate tty for git clone. Default value is false.
set('git_tty', true);

// Shared files/dirs between deploys
add('shared_files', ['.env']);
add('shared_dirs', ['storage']);

// Set number of releases to keep
set('keep_releases', 3);

// Writable dirs by web server
set('allow_anonymous_stats', false);

// Host
host('ipv6')
    ->set('labels', ['stage' => 'production'])
    ->set('repository', 'git@company:site/brand-site')
    ->set('branch', 'main')
    ->set('remote_user', 'root')
    ->set('http_user', 'root')
    ->set('deploy_path', '/var/www/www.site.co.uk');

// Tasks
task('deploy', [
  'deploy:prepare',
  'deploy:lock',
  'deploy:release',
  'deploy:update_code',
  'npm:install',
  'composer:install',
  'deploy:shared',
  'deploy:writable',
  'deploy:vendors',
  'brand:publish:vendor:public',
  'brand:npm:build',
  'deploy:clear_paths',
  'deploy:symlink',
  'brand:route:clear',
  'deploy:unlock',
  'deploy:cleanup',
  'deploy:success'
]);

I'm trying to deploy to my server, but Deployer seems to keep locking on deployment and doesn't return an error other than telling me it's locked.