Apple Job Application Cannot Remove Optional Information Files

I am applying for a position at Apple. On the application site you can add optional information such as cover letters. I uploaded a cover letter but decided to modify it and re-upload it. I can add and remove the new one but cannot get rid of the old cover letter that is still there. When I click the Remove button, the errors shown in the image are thrown.

I have both signed out of my account and signed back in, as well as refreshing the page. How should I proceed with this?