next/image "url" parameter is valid but upstream response is invalid

Problem

Verify canary release - [X] I verified that the issue exists in the latest Next.js canary release Provide environment information [code block] Which area(s) of Next.js are affected? (leave empty if unsure) Image optimization (next/image, next/legacy/image) Link to the code that reproduces this issue or a replay of the bug https://github.com/luca-vogels/bug-next-image To Reproduce Run `npm run dev` or `npm run build && npm run start` Describe the Bug When using next with a custom server like express images are not displayed anymore. Default next image uses following route for fetching optimized images: `/_next/image/?url=...&w=...&q=...` However opening this route returns following error: `"url" parameter is valid but upstream response is invalid` Expected Behavior Optimized image is returned Which browser are you using? (if relevant) 115.0.5790.111 How are you deploying your application? (if relevant) npm run start _NEXT-1681