Migrate RDS MySQL to RDS Postgres Connection Error: Timeout Expired Cannot Connect to ODBC provider Network. How to connect to databases and make migration?

I'm attempting to migrate an RDS MySql db to a RDS Postgres db. I've made a new postgres db to copy to, the source db is live - website is accessible and works with database requests. I'm using the AWS DMS database migration service, but am unable to successfully connect to either database in my endpoint testing, or from my command line or from the sqlectrong gui. I'd like help debugging this issue connecting with my databases.

I've tried updating my security group inbound rules to accept all TCP traffic for postgres and mysql ports. I've tried making my db open to the public. Both databases are listed as active. I'd love some help resolving these issues, so I can connect to my databases then migrate mysql to postgres.

I'm getting this error in my AWS DMS endpoint testing for the new postgres db: postgres-testing-1 postgres-migration-test failed Test Endpoint failed: Application-Status: 1020912, Application-Message: Cannot connect to ODBC provider Network error has occurred, Application-Detailed-Message: RetCode: SQL_ERROR SqlState: 08001 NativeError: 101 Message: timeout expired

I'm also getting this error when trying to connect to the database from sqlectron: Connection Error Error invoking remote method 'DB_CONNECT': error: no pg_hba.conf entry for host "216.201.187.254", user "vance", database "initial_db", no encryption