Jmeter bypassing the environment variable that been set in user defined variables and running other environments in Tests

I have an issue with jmeter test setting that after initializing the environment as PROD in user defined variable and in a specific thread group I have tests to run on basic environment & UAT environment only . But these tests are passing even when ran on the PROD environment. My question is when PROD environment are running why are the UAT/Basic tests passing!? is there a solution to this issue?

 The 3 environments I have
1) env= PROD
2) env = BASIC
3) env = UAT