The issue could be with the response you are receiving from back-end. If it was working fine on the server then the problem could be with the response headers. Check the Access-`**Control-Allow-Origin (ACAO)**` in the response headers. Usually react's fetch API will throw fail to fetch even after receiving response when the response headers' ACAO and the origin of request won't match.
for more information [link][1]

[1]: https://medium.com/@baphemot/understanding-cors-18ad6b478e2b

The issue could be with the response you are receiving from back-end. If it was working fine on the server then the problem could be with the response headers. Check the *Access-Control-Allow-Origin* (ACAO) in the response headers. Usually react's fetch API will throw fail to fetch even after receiving response when the response headers' ACAO and the origin of request won't match.