To be able to help you debug this, it would be useful to have more details about what you have attempted. Can you detail the changes you have made, the steps you have taken to apply these changes, where you’ve made them, how your environment and installation is setup, whether it’s a devstack or a prod install, etc. Have you checked that the configuration changes are applied? What steps have you attempted to debug it?
In newer versions of Open edX, you must make the change in /edx/etc/lms.yml instead of lms.env.json. Perhaps that is your issue? If not, additional information and logs would be needed to debug the info, as @antoviaque said.