Serverless Framework and CloudFormation coexistence

We are creating a S3 bucket with CloudFormation yaml, then we create a Lambda function with Serverless Framework.

If we add s3 events to lambda on the Serverless Framework yaml using the bucket created in CloudFormation it works perfectly.

But if we modify s3 bucket Cloud Formation Stack, it remove all s3 events added with Serverless Framework.

Is posible to keep this s3 events in lambda function when we launch the CloudFormation s3 stack ?

Thanks !!

Okay so I worked at a few places that used serverless.yml / serverless.template as the package to deploy stacks to lambda / API gateway. Now never really using cloudformation directly despite the auto gen one serverless creates. I am curious what is a better one to use? If serverless the preferred way? To deploy API gateway / lambda functions? When creating Kodi nox api’s?