In some cases Google Contacts won't show any other address book account on Android 12.
To make it show up again you either need to
- completely un- and reinstall Google Contacts or reset/wipe data of this app.
- or you need to trigger the access to these address books once. The easiest way is to install another contacts app: for example "Simple Contacts" from the Play Store. Once you opened it and showed the available address books, they will also show up again in Google Contacts [recommended].