Crossorigin error

Hi guys. i have a problem in my wordpress. i’ve moved my upload folder to a subdomain. every thing is good, except when i add subtitle to a video i get this message in the inspect elements console and the subtitle doesn’t load.

Text track from origin 'https://fa-media.fardacademy.com' has been blocked from loading: Not at same origin as the document, and parent of track element does not have a 'crossorigin' attribute. Origin 'https://fardacademy.com' is therefore not allowed access.

XMLHttpRequest cannot load https://fa-media.fardacademy.com/2015/04/1523621.vtt. No 'Access-Control-Allow-Origin' header is present on the requested resource. Origin 'https://fardacademy.com' is therefore not allowed access.

What should i do? What’s the solution except moving back my upload folder to wp-content?

thanks in advance.