The 'children' which I comment out (and fixes my issue) is a simple page.tsx wrapped in a Suspense boundary:

You would expect it to route instantly, and show the suspense boundary

Verify the behavior in a production build. During development the server compiles on the fly and isn't as fast as a pre-built app.

Yeah I’ve tried a production build

I might be having a similar issue. Clicking on a link means about one second of no response at all. Then it finally goes to the page. I've tried addin a loading page and no change