Unified_audit_trail gets filled with unwanted data even if no audit is being done

Hi,
We have a Database 19c that was migrated from an 11g. Currently the auditing is in mixed format.
I noted that the unified_audit_trail is being populated with data even though all auditing options were disabled.

There's nothing in the views dba_stmt_audit_opts, dba_priv_audit_opts and dba_obj_audit_opts and dba_audit_policies.
All default Unified Audit Policies were also disabled (ora_secureconfig, ora_account_mgmt, ora_cis_recommendations).
The view audit_unified_enabled_policies is also empty.

I'm still seeing millions of records being added to the unified audit trail.

What am I missing?