elasticbeantalk for Ruby platform does not respect .ruby-version

I deployed my app to elasticbeantalk on arn:aws:elasticbeanstalk:ap-northeast-1::platform/Ruby 2.7 runnin on 64bit Amazon Linux 2/3.4.4.

It prepares Ruby 2.7.5 via rbenv, so I set .ruby-version to 2.7.5 in my repository. Then I deployed same app to another env with platform version 3.4.8. New env prepares Ruby 2.7.6. However, deployed app is working fine.

Is this expected behavior? Why .ruby-version in the repository is not respected?