Lost connection to MySQL server when scaling RDS Aurora Cluster

Hello, we're having some difficulty with our primary AWS Aurora Clusters and the various webservers that connect to them. Whenever a scaling operation occurs - both scaling up and scaling down - a large number of connections to the database are rejected ( 2,000+ ). We have noted the following errors from the RDS event log and our webservers:

The DB cluster failed to scale from 64 capacity units to 32 capacity units for this reason: A scaling point wasn’t found.

OperationalError: (2013, "Lost connection to MySQL server at 'reading initial communication packet', system error: 0")

We have attempted to debug this problem with the following steps, but nothing has helped us to resolve it so far:

• Reviewed MySQL error logs in Cloudwatch ( these only provided the server-level errors, nothing from RDS specifically )
• Turned off general MySQL logging
• Ensured Apache / MySQL connection timeouts did not exceed the RDS Autoscaling Timeout
• Verified all VPC, IGW, Route Table, and subnet settings associated with the instances connecting to the database.

Below is some information regarding the cluster.

Cluster Version:

• Aurora MySQL (compatible with MySQL 5.6.1.22.3)

Capacity Settings:

• Minimum ACUs 16 - 32 GiB RAM
• Maximum ACUs 64 - 122 GiB RAM

Additional Scaling Configuration:

• Autoscaling timeout and action: 00:05:00
• Do this: Roll back the capacity change

Any advice or insight into possible avenues of troubleshooting or debugging would be highly appreciated at this point.