I have an action button in a form that opens a view for web users.
However, I can’t restrict the view to a single category. The URL is correct, but no matter what category I enter, all documents in the view are displayed.
The view has three columns, and only the first one is categorized.
matches your pattern, and it does work. So there’s something about your specific URL or your specific view or the way you’ve embedded it in the form you’re displaying it in, that’s stopping it from working. But you’ve given few specifics.
I only respond twice to a given thread, so I’m bowing out of this one. I hope you can figure it out. If you add some details perhaps someone else can help. Try to think of some tests you can do to narrow down the source of the problem. For instance, rename your view template form(s) and see whether you have the same problem with the default view rendering.