When you say "is not working in uat" what is the problem? Do you see any error messages in the UI or in the log?
Assuming you have cleared the browser cache between tests and perhaps also restarted the browser between tests and you are still seeing a difference in behavior between the two environments, you can safely assume there is a difference between the two environments.
Are you deploying the exact same AMP to DEV as you are to UAT?
Do both environments have the exact same set of AMPs installed (including version of each)?
Has anyone made changes that are not included in an AMP, such as touching Alfresco's files or adding extensions to Tomcat Shared?
What gives you the confidence that DEV and UAT are identical?