I am only able to connect to a MySQL Aurora cluster's reader endpoint and read replica instance endpoints. However, connection timeouts occur when connecting to the cluster's writer endpoint and the primary writer instance's endpoint.
Additional details:
- Using MySQL Workbench
- Using Cluster's master username/password
- Access to VPC through VPN
- Cluster SG has VPN IP range whitelisted
- Traffic allowed through subnet NACL's
- Cluster instances in private subnets
Any thoughts what might be causing this issue?