Elastic Beanstalk environment does not terminate

Hello.

What kind of error is occurring specifically?
Also, ElasticBeanstalk creates a CloudFormation stack on the backend, so checking the CloudFormation stack may reveal the cause of the error.
If you don't need the ElasticBeanstalk environment, you should be able to delete it by directly deleting the CloudFormation stack.
The following document focuses on security groups, but I think it can be used with other AWS resources in the same way.
https://repost.aws/knowledge-center/elastic-beanstalk-deletion-failure