Unreachable datasource stops other working datasources

What did you do?

We are using an image of postres-exporter in our docker-compose for which we successfully configured two datasources.
Yesterday we added a third datasource which we have just seen it is unreachable.

The issue I want discuss is, why the other two datasources stopped working? We have found the issue looking at our Grafana where before adding third datasource we regularly could see

What did you expect to see?

What did you see instead? Under which circumstances?

Environment

We are using prometheus 2.28.1 image inside a vm hosted in our cloud

• System information:

Linux 3.10.0-1160.31.1.el7.x86_64 x86_64

• postgres_exporter version:

  postgres_exporter, version 0.10.0 (branch: HEAD, revision: 57719ba53cac428769aaf3c4c0bb742df3cfca98)
  build user: root@4dcb2c7f1315
  build date: 20210709-11:49:20
  go version: go1.16.5
  platform: linux/amd64

• postgres_exporter flags:

insert list of flags used here

• PostgreSQL version:

  insert PostgreSQL version here

• Logs:

insert logs relevant to the issue here

Start by reproducing the setup described for postgres_exporter 0.10.0 with two working datasources and a third unreachable datasource, using the provided Prometheus and Linux environment details. Collect the missing flags, PostgreSQL versions, and logs, then verify that the working datasources continue to produce metrics when one datasource cannot be reached.