Private distribution app does not appear in the custom app

Hello, I am having trouble distributing the internal app to the Apple Business Manager via the AppStore private distribution.

== Steps to reproduce ==

1. Create a new app on AppStore Connect
2. Set it as a private distribution and specify the organisation ID
3. Submit the build to the review
4. The app review is approved and "Ready to Distribute"

On the distribution tab, it says "This app was removed from sale from the App Store. Go to Pricing and Availability to add it back to the App Store."

1. Sign-in to the Apple Business Manager
2. Enable the custom app in the Apple Business Manager settings

Expected: 7-A. The app is listed under the Custom App

Observed: 7-B. There is no app listed under the Custom App section

== Questions ==

1. Is there any other steps for the successful private distribution?
2. Does the organisation receive any email from the App Store Connect to accept the private distirubion?
3. Is there any way to see the status of the custom app from the developer?
4. Is there any Apple support contact I can confirm the status of the app?

Thank you for your help in advance!