Tableau Snapshot with External filestore and External Repo failed to tag snapshots.

I am trying to run the snapshot process for Tableau. Following the documentation, the first step is to run the command

tsm maintenance snapshot-backup prepare

However running this command fails within a few seconds while trying to tag snapshots

5% - Generating name and path for backup temporary file.

10% - Starting the Active Repository instance, File Store, and Cluster Controller.

15% - Waiting for the Active Repository, File Store, and Cluster Controller to start.

21% - Installing backup services.

26% - Estimating required disk space.

31% - Gathering disk space information from all nodes.

36% - Analyzing disk space information.

42% - Checking if sufficient disk space is available on all nodes.

47% - Backing up configuration.

52% - Failed to tag snapshots.

57% - Stopping the Active Repository if necessary.

63% - Waiting for the Active Repository to stop if necessary.

68% - Uninstalling backup services.

Preparation for snapshot backup failed.

Note that if you have already run this command, you must run tsm maintenance snapshot-backup complete before running this command again.

This job failed due to unexpected error: 'TApplicationException'

failed to tag snapshots

Looking in the backuprestore logs, I see an error message:

Caused by: org.postgresql.util.PSQLException: ERROR: permission denied for schema public

I then checked the metadata server logs (Aurora RDS PostgreSQL) and I see these cryptic error messages:

2025-03-18 19:01:46 UTC: IP (54832):rails@workgroup:[36404]:ERROR: permission denied for schema public at character 28

2025-03-18 19:01:46 UTC:<IP >(54832):rails@workgroup:[36404]:STATEMENT: CREATE TABLE IF NOT EXISTS nats_snapshot(jsondata text)

This doesn't make any sense as rails is the master user for the database instance and has access on all schemas including public. I logged in as rails and ran this statement and it ran without any issues - creating a table in the public schema under the workgroup database.

Is there anything else I am missing? I don't see an option to increase debug logging but the database log is pretty clear. I don't understand why it wouldn't be able to run this statement.