pm2 script execution path is incorrect, doesn't match the one in ecosystem.config.js

My ecosystem.config.js looks like this:

module.exports = {
apps: [{
    name: 'production',
    script: '/home/username/sites/Website/source/server.js',
    env: { NODE_ENV: 'PRODUCTION' },
    args: '--run-server'
}, {
    name: 'staging',
    script: '/home/username/sites/WebsiteStaging/source/server.js',
    env: { NODE_ENV: 'STAGING' },
    args: '--run-server'
}],
deploy: {
    production: {
        user: 'username',
        host: ['XXX.XXX.XX.XXX'],
        ref: 'origin/production',
        repo: 'git@github.com:ghuser/Website.git',
        path: '/home/username/sites/Website',
        'post-deploy': 'npm install && pm2 reload ecosystem.config.js --only production',
        env: { NODE_ENV: 'PRODUCTION' }
    },
    staging: {
        user: 'username',
        host: ['XXX.XXX.XX.XXX'],
        ref: 'origin/staging',
        repo: 'git@github.com:ghuser/Website.git',
        path: '/home/username/sites/WebsiteStaging',
        'post-deploy': 'npm install && pm2 reload ecosystem.config.js --only staging',
        env: { NODE_ENV: 'STAGING' }
    }
}
};

When I deploy the application, I expect to see two processes - one called 'production' and one called 'staging'. These run code from the same repo, but from different branches.

I do see two processes, however, when I run pm2 desc production I can see that the script path is /home/username/sites/WebsiteStaging/source/server.js. This path should be /home/username/sites/Website/source/server.js as per the config file.

I've tried setting the script to ./server.js and using the cwd parameter but the result has been the same.

The deploy commands I am using are pm2 deploy production and pm2 deploy staging and I have verified that both the Website and the WebsiteStaging folders are present on my server.

Is there something I'm missing here? Why would it be defaulting to the staging folder like this?

from pm2 script execution path is incorrect, doesn't match the one in ecosystem.config.js