Metrics from multiple RDS instances on different versions not shown

What did you do?
Configured exporter to pull metrics from multiple instances via DATA_SOURCE_NAME environment variable with a comma separated list. All targets are RDS, some of them are on Postgres version 11.x, some on 12.x and 13.x, however looks like the exporter is not happy when I try mixing the versions as no metrics are shown. If I configure the exporter to pull only from database running on version 11.x, it is okay, metrics are shown, same goes for 12.x and 13.x, but not all together.
I am not sure if this is expected or not?

What did you expect to see?
Metrics, lots of them, from multiple RDS versions :)

What did you see instead? Under which circumstances?

Environment
Exporter running in Kubernetes cluster on EKS

• postgres_exporter version:
  v0.10.1
  v0.11.0
  v0.12.0-rc.0

• PostgreSQL version:
  11.x
  12.x
  13.x

• Logs:
  No errors in the logs, it is making successful connection to each database regardless of database version

Start with the DATA_SOURCE_NAME entry point and reproduce the issue using mixed PostgreSQL 11.x, 12.x, and 13.x RDS instances. Compare the exporter’s exposed metrics and connection behavior with single-version configurations; done means metrics from all configured versions are shown together.