Why is my function middleware not active?

I created a middleware here: https://github.com/NullVoxPopuli/limber/pull/1733/files

and locally, testing with npx wrangler has the desired behavior.

but when I view my page's latest deploy: https://4186709a.limber-glimmer-tutorial.pages.dev/1-introduction/1-basics

the middleware is not active.
What debugging steps should I try?
Interactive tutorial for learning Glimmer, Ember's reactivity and component system, as well as the syntax and patterns needed to be effective in Glimmer and Ember projects.
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