Error 302 is triggered while document is uploaded

On our website, we have a Job posting page where someone could upload their CV.
Since few weeks, people who try to upload their document (docx and pdf) got error 302, which is a redirection, while the document is sent and the upload fail.

We don’t have multiple servers or cluster. Do you know any setting we could verify on Cloudflare that could prevent the url from changing while document is uploaded?

Thanks