Symfony: Switch to prod with dev changes on hosting

I did maybe something wrong but need to fix this somehow.

I have an application with Symfony 4, uploaded on some hosting server. I transfered it in DEV mode (didn't know that it's bad) and now if I set

APP_ENV=prod

in .env.

The web presenting some old state. When I switch back to dev the current state is visible.

On local when I switch to PROD I can see current version too, so I don't know what to do.

Do I need to switch the project to the PROD on local and then transfer it again to server?

Isn't there any way how to switch from dev to prod and see current state?

When I looked to the twigs etc. I can see current state, so it's weird.

Thanks for help