Metabase in Elastic Beanstalk connecting to uncoupled RDS broken

We have a Metabase instance running with Docker in EB in AWS. There is an uncoupled PostgreSQL RDS that hosts the Metabase data. All was running fine for a while, but several weeks ago the instance stopped working and now only serves 502 gateway errors. Going through the logs I'm seeing this error which I suspect is at the root of the issue. It seems to reflect that Metabase isn't able to start as it cannot access the RDS for some reason and is leading to the Docker container being continually killed and restarted:

org.postgresql.util.PSQLException: FATAL: no pg_hba.conf entry for host "", user "xxx", database "xxx", SSL off

I did not set up this instance, so I've been trying to get a handle on Metabase/docker/RDS through the setup documentation. Nothing was changed in the environment though Docker updates were being auto applied, which I've since stopped and attempted to roll back. All the connection variables are there in the EB configuration and appear to be correct. I assume that there is no pg_hba.conf entry as this file would only exist if we were running the database locally, which we are not and have not since initial launch. Been on with AWS support and they keep coming back to it being an application problem but I don't understand what could have changed to break it.

Feel like I'm jumping all over the place with the troubleshooting on this and going in circles. Hoping someone can help me hone in on what's going on here - I got the nagging feeling that this is not a complicated issue but I'm stuck circling it. Thanks!

Hi @rpete
I'm sure you have read the documentation, but you're not referencing it, so here's a link:

Have you tried to spin up a new RDS (with the data from the old) and a new EB connecting to the new RDS?
It's not like you can break anything (just make sure that you have backups of the RDS data).

It's difficult to know more without logs, which should help pinpointing exactly when it stopped working - because it's very rare that computers stop working without some type of change somewhere.