Hide exceptions in production envairoment

I have started the migration of my current application at CI 3 to CI 4. Wow.. a lot of changes

I have seen that the bugs in CI4 are very detailed, and debuggers have been included, it looks good! 

But for a production environment they bring too much information, so I have modified the variable CI_ENVIRONMENT in my .env file by production and I have tried to generate an exception from the example Home controller. 
The result is practically the same as if I am in development. (I've checked that the variable is loaded correctly)

What am I doing wrong?