[Question] SSL error when connecting to AWS RDS

This maybe not be a bug, but Postico complains SSL error when connecting to AWS RDS servers even though I registered AWS RDS root CA to my system keychain.
Is there any workaround other than registering each certificates for every AWS RDS server?
Or am I missing something?

## What did you do?

- Add AWS RDS Root CA to system.
- Connect to AWS RDS via Postico.

## What did you expect to happen?

- Connection opens without an error.

## What actually happened?

- Postico complains that certificate is not standard compliant.
-

## What software versions are you using?

Postico version: 1.5.18

macOS version: 11.2.3

PostgreSQL version: PostgreSQL 11.10 on x86_64-pc-linux-gnu, compiled by gcc (GCC) 4.8.5 20150623 (Red Hat 4.8.5-11), 64-bit

No source files, tests, or entry points are named. Start by reproducing the connection from Postico 1.5.18 on macOS 11.2.3 against PostgreSQL 11.10 on AWS RDS, using the reported system-keychain setup. Done means determining whether the AWS RDS root CA is accepted and whether a connection can open without the certificate error.

Written by the indexing model from the issue text.