Aurora Serverless (PostgreSQL) autoscaling error

Hello,

I am seeing these errors in my Aurora instance:

1:32:59 PM UTC: The DB cluster has scaled from 2 capacity units to 4 capacity units, but scaling wasn't seamless for this reason: An internal error occurred.
1:33:13 PM UTC: DB instance restarted

Applications connected to the database experience errors when it happens:

psql: error: server closed the connection unexpectedly
        This probably means the server terminated abnormally
        before or while processing the request.

Any ideas on what would be causing these errors and how to prevent them? Thanks.