Grafana: MongoDb - server selection error: server selection timeout

Hi, I’m trying to use MongoDB datasource plugin and using DigitalOcean MongoDB instance. I have no problem connecting to my DB through other clients but can’t set up connection through plugin setup page. Mongo logs shows connection accepted and immediately connection ended. Plugin shows following error server selection error: server selection timeout, current topology: { Type: ReplicaSetNoPrimary, Servers: [{host, Last error: x509: certificate signed by unknown authority }}]. Can anyone help me please?

I was able to connect to DB if tls=false. But my queries ending up being refused by (InvalidNamespace) Invalid database name:.