Why isn't my store currency changing despite enabling all countries?

[eclectickart]

 Hello , i have been trying for so many hours as my Shopify is showing USD (primary currency) for the other country currencies too. Whenever i switch to any other country , my store still shows USD for any other country excluding United States. I have enabled all the countries in markets and already changed the format. There are no third party applications and my theme is already set alright. Please someone help me out.