I've got a site that was running NextJS 12 but had an issue where all 404 pages were resulting in 500s so I've upgraded to the latest NextJS 13.4.16 as I had heard it could be a version issue.
This has fixed the 404 error has now the 404 page is getting displayed, However I've got a different issue -

Any requests to _next/image?url=... or _next/data/something.json are resulting in a 404.
These were working correctly on amplify with the v12 build.
Deploying to Vercel and everything works fine, so I'm not sure what it could be.

The only redirect I have is the default

/<*> => /index.html 404 (rewrite)

I'd love any help here to track this down.