Fresh install, CI_DEVELOPMENT in .env not work

Hi all, i try to install fresh codeigniter from composer again

Code:

composer create-project codeigniter4/framework ci-news

again, i rename 'env' files to '.env', and change :

Code:

#CI_ENVIRONMENT = production

to

Code:

CI_ENVIRONMENT = development

then i do in terminal 

Code:

php spark serve

the result still in 'PRODUCTION ENVIRONMENT'.
Please anybody can reproduce it? Thanks