Issues with UTM Params Not Being Tracked Automatically in Production

Context:

I have a website that redirects users to my app with a series of UTM parameters in the URL. At that point, I want to track an event, but I do not have a user in my app yet, so I only send the event without any user information. For some reason, the UTM parameters are not being automatically managed by Amplitude. I have two questions regarding this:

1. In other parts of my app (where the user exists), the UTM parameters are being saved automatically by Amplitude. Do I need to have a user and send user information for UTM parameters to be automatically managed by Amplitude?

2. The issue only occurs in the production environment; it works fine in a development environment. Is it possible that I need to configure something additional in the production environment?

Stack:

• "@amplitude/analytics-browser": "~2.8.1"
• "@amplitude/ampli": "~1.35.0"

This is my implementation for sending events:

ampli.load({ 
  environment: 'production',
  client: {
    configuration: {
      defaultTracking: {
        attribution: true,
        pageViews: false,
        sessions: false,
        fileDownloads: false,
        formInteractions: false,
      },
      trackingOptions: {
        ipAddress: false,
      }
    }
  }
});

if (user) {
  ampli.identify(user.id, userProperties);
}

ampli.track(event);
ampli.client.flush();