Custom 404 pages do not work on the dev server

[eleanorreem]

Describe the bug
Our custom 404 pages are not working on the dev server but they do seem to work if you build the app. This only happened after the upgrade to nextjs 13.5.4

To Reproduce
Steps to reproduce the behavior:

1. Run the bloom-frontend with yarn dev.
2. go to localhost:3000/123
3. See default Next js 404 page.
4. Exit dev server
5. Run yarn build
6. Run yarn start
7. go to localhost:3000/123
8. See Custom 404 page which is src/pages/404.tsx

Expected behavior
On the dev server, we should be able to see the custom 404 page.

Screenshots
Nextjs Default

Custom 404

Desktop (please complete the following information):

• Macbook Pro 2021, Mac Os Monterey 12.2
• Browser Chrome
• Version 117.0.5938.132