Blocked by CORS Policy

Hello,
please need some help. My site has been running fine but today I suddenly started getting these errors and the site not loading properly and sometimes an Error 521 Web Server is Down. When I access the console from inspect tool I get this error message.

Access to XMLHttpRequest at ‘https://www.umojami.com:2053/socket.io/?hash=6437294860f322338637&EIO=3&transport=polling&t=NdjaD-P’ from origin ‘https://www.umojami.com’ has been blocked by CORS policy: No ‘Access-Control-Allow-Origin’ header is present on the requested resource.

Please can anyone help?

Thx