How to migrate my application seamlessly from Sandbox to QA environment

Hello I built multiple environments with AWS Organizations - Sandbox and Testing. My application has Amazon Lex V2 and Lambda attached to Lex. I've tried export/import on Lex and Lambda to promote the dev work to testing environment, but the fallbackIntent in the Lex bot is always broken. so I am worried about promoting to testing environment using manual export/import. Is there any other efficient/seamless way to migrate the resources to another environment(organizational unit)?

Thank you !