Always need to clear cache for .env changes to take effect?

Check APP_ENV in your .env file, if it’s value is correct (production in OP’s case) then yes, Laravel is caching it.

Once cached, the .env file is ignored, and env(...) function returns null.

You should run these commands after changing configs:

php artisan cache:clear
php artisan config:cache
php artisan route:cache
php artisan optimize

Note that “php artisan config:cache” may be enough, but changing APP_ENV could add or remove routes or something like that (is your App, you know better).