Interacting with RDS as a true superuser (rdsadmin) or how to grant user access to modify pg_catalog tables?

Hello, I'm currently using RDS Postgres (Postgres v14 if it matters) and I've hit an issue with corrupted content of pg_catalog tables (pg_class in this case) rendering the DB mostly unusable. I'm stuck on error

pg_dump: error: schema with OID xxxxxxx does not exist

when trying to dump a schema.

The master user for the instance however does not have permissions to modify any of the tables' content, nor is it possible to grant him the privileges to do so.

Is there a way around this?

I understand rdsadmin is only used internally by RDS to manage the instance and there is a reason for this limitation, but is there a workaround to handle this scenario without having to replace the whole RDS instance?

Thanks!