All these days the terraform script worked fine with the version 5.7.mysql_aurora.2.07.1 suddenly from today noon onwards we started to face this weird upgrade issue.
The last automated build also deployed the cluster with above version. After checking the aurora version using the below command
select aurora_version();
select @@aurora_version;
the result was 5.7.serverless_mysql_aurora.2.08.3 it was shocking to know somehow the server got upgraded to this new version.
Solution: All we need to do is keep the new version in the terraform and everything started working fine.
Warning: Ensure your DB is backed up before you do any modification on the server.