Lambda RDS Postgres not working

Question

I'm trying to make rds with postgres work with lambda, but no luck so far. I've read all other threads about it here, double-checked my Lambda VPC + Subnet config, it's the same as the RDS one, but still no luck connecting, what am I missing here?

Some screenshots to clarify: 

Before, I enabled the Public access and I could connect through serverless offline.

Thanks!

EDIT ---- 

Answer 1

Have you verified your security group for your RDS service? It needs to allow access from the security groups given to your Lambda function. It is not enough that they are in the same VPC/subnets. The security group still needs to allow traffic on the ports for postgres (5432).

Note that for security groups you don't have to select an origin IP (which can be tricky for Lambda). But i notice you are giving your Lambda function the group sg-29aac25d. You can use that ID to give access to the RDS.

IAM policies should be irrelevant as you are authenticating against postgres. Unless your IAM doesn't allow your Lambda to execute, the problem is not IAM.