I just wrote up a pretty comprehensive article walking through the steps required to get trailing slashes working everywhere. Might be worth a read for you:
Otherwise, I checked out your site and, assuming you still have “Pretty URLs” still enabled for your site, I think what I can see from some CLI HTTP requests is that you’re missing a nesting layer. In canonical / historical web parlance, a URL’s path with a trailing slash represented a directory and a path without represented a document. The “Pretty URLs” feature helps accommodate that history but still adheres to it. If you have a document,
/work/equall.html, Pretty URLs will convert it to
/work/equall but not add a trailing slash because it’s a document, not a directory.
If instead you rename that file
index.html and nest it inside a named folder, Pretty URLs will enforce a slash and treat it like a directory. E.g. change
/work/equall/index.html. In this case, Pretty URLs is always going to enforce a trailing slash because the user is looking at a directory, not a single document.
I hope that makes sense and helps. No _redirects or anything needed!