RDS session_replication_role in paramater group is not being applied to all sessions

Question

I've just finished migrating some postgres RDS instances from 9.6 to 12.8 using AWS DMS. After changing the session_replication_role back from replica to origin on the instances that were previously targets (using the parameter groups), I've realised foreign key constraints and triggers are not being enforced for all users (only the master account).

For instance, show session_replication_role returns a value of origin for the master account, but replica for the users our applications connect to the various dbs with. The parameter group is showing as being synced and I've gone through a couple of reboots just to make sure. Anyone have any idea about why this is occurring or encountered this issue before?