Client-side navigation issue with fallthrough routes in production

[qriosdev]

Objective
I'm building a static site that has dynamic [category] and [post] routes. The [category] checks if a category exists. If it does then it's supposed to return a list of posts from that category to display. Else, it should fall through to [post].

Issue
When I build and preview locally everything works as planned. But once deployed to Cloudflare Pages or Netlify client-side navigation to category pages doesn't return posts belonging to that category. I can see route and page title changing but the rest of content stays the same. But if you refresh or go to category pages directly everything shows correctly. Not sure if it's a bug or me not understanding how fallthrough routes work.

Project Details
I'm providing a test project repo that's deployed to both Cloudflare Pages and Netlify here if someone wants to take a look. Both has the same issue.

Repo: https://github.com/qriousdev/lot-kit
Cloudflare Pages production: https://lot-kit.pages.dev/
Netlify production: https://elastic-noether-01ccd1.netlify.app/category1