PDO::prepare(): MySQL server has gone away

I am getting PDO::prepare(): MySQL server has gone away error in my error logs. After the RDS Aurora mysql version upgrade i am getting this error simultaneously. I am not able to find the root cause of this error. current version of mysql is 2.10.3.

I follow this post but no luck. https://aws.amazon.com/premiumsupport/knowledge-center/rds-mysql-server-gone-away/