After building my app also generated sitemap.xml and feed.xml.
But I don’t have access to this file. I know these files created because I get message about it from the callback function.
I test this process on my local machine - and this works fine.
I have no idea what’s wrong with it.
Just for clarification: app developed with Next.js (static blog) and files to be created with 774 permissions in “publish” directory.
Also, this problem exists with robots.txt file.
UPD: Clear cache & redeploy fix it =)