Python Lambda Function Cannot Access MemoryDB

Hello, I'm trying to write a Python 3.11 lambda function that will talk to Amazon MemoryDB. When I include the redis connection and a simple "get", the function hangs and times out after a few seconds.

Things I've ensured:

• Lambda function is running on the same VPC as MemoryDB
• Security Group for both Lambda and MemoryDB are both set to allow Inbound and Outbound 6379.
• Lambda function and MemoryDB are in the same subnet

The cluster endpoint looks like this: clustercfg.my-cluster-name.xyz123memorydb.us-east-2.amazonaws.com:6379

My connect and get look like this:

import json
import redis

r = redis.Redis(host='clustercfg.my-cluster-name.xyz123memorydb.us-east-2.amazonaws.com', port=6379, decode_responses=True)
r.set('foo', 'bar')

Running the above hangs for a few seconds, times out and then dies. The lack of ability to do simple things like pinging or CLI connection to redis from the "host" that the function runs on makes it hard for me to troubleshoot. Any ideas on where I can start to troubleshoot here and how to fix this issue?

Thanks! -Brett