Physical _redirects file being interpreted as a function, not a file

I have a postbuild step in my Next.js app that runs node to run a .mjs file that generates /public/_redirects as a physical file. It runs correctly locally and the Netlify build logs show the script runs, but when I try to access the file in the browser it seems to be interpreted as a function, not the physical file:

Hi @mursino , Welcome and thanks for the post.
Based on the comments from the official Netlify Issues page below the _redirects files is not supposed to be accessible publicly when you hit path appended with the _redirects