Run php in post is redirecting to index.php

I am using a man page php script in my blog and when I submit the query, I am redirected to the top level index.php page.
Try it out here: https://mochabomb.com/blog/archives/category/man-pages-unix/
You’ll end up back at the main page. This is a problem because as I post it get buried down in the list. Not sure where to start on this one.