Link to the code that reproduces this issue

https://github.com/rikbrown/nextjs-rdc-prefetch-hang-on-vercel

https://vercel-rdc-deep-dive-ql5p89xy5-rikinsearchofas-projects.vercel.app/en/static-page

To Reproduce

The provided reproduction consists of a top-level layout with several dynamic pages (and a static page). There is a loading.tsx boundary around most of the pages. Each dynamic page is configured to await connection() then sleep for a second to mimic a dynamic network request. In addition, there is one extra dynamic page which has no loading boundary, but instead implements it itself using Suspense.

1. Deploy the application to Vercel (pnpm vercel deploy)
2. Visit the application e.g. https://vercel-rdc-deep-dive-ql5p89xy5-rikinsearchofas-projects.vercel.app/en/static-page
3. Click on link (prefetch=true) to dynamic-page-1: observe that the children UI hangs on "Page Loading..."
4. Hard-refresh: observe that the children UI resolves after 1s to "Dynamic Page 1 Loaded"
5. Click on the prefetch=auto or prefetch=false links and observe their associated pages load correctly after 1 second, or the static page link which loads instantly.
6. Click on the dynamic-with-suspense link, which is also full prefetched, and observe that the page loads and hangs at the Suspense boundary (in fallback) - the same effect but proving not just a loading.tsx issue.

Current vs. Expected behavior

As described above, it seems like Suspense boundaries often hang indefinitely when deployed on Vercel when they act as the boundary for a dynamic segment. This occurs only when prefetch={true}: it does not occur with auto or no prefetching.

Provide environment information

This is my local environment, but it does not reproduce on next start. I can only reproduce this in Vercel (nb: have not tried any other cloud providers).

Update 10/22: can confirm this is an issue on the just-released Next 16 stable

Operating System:
  Platform: darwin
  Arch: arm64
  Version: Darwin Kernel Version 25.0.0: Wed Sep 17 21:41:26 PDT 2025; root:xnu-12377.1.9~141/RELEASE_ARM64_T6041
  Available memory (MB): 131072
  Available CPU cores: 16
Binaries:
  Node: 22.18.0
  npm: 10.9.3
  Yarn: 1.22.22
  pnpm: 10.18.3
Relevant Packages:
  next: 16.0.0-canary.16 // Latest available version is detected (16.0.0-canary.16).
  eslint-config-next: N/A
  react: 19.2.0
  react-dom: 19.2.0
  typescript: 5.9.3
Next.js Config:
  output: N/A

Which area(s) are affected? (Select all that apply)

Dynamic Routes, cacheComponents, Linking and Navigating, Partial Prerendering (PPR)

Which stage(s) are affected? (Select all that apply)

Vercel (Deployed)

Additional context

After bisecting this, I identified this change started affecting us when rdcForNavigations was made default in 16.0.0-canary.6. However, if I go back to canary.5 - it does not occur if rdcForNavigations is false, but does occur if I turn on the experimental flag.

I have not tried patching Next.js to turn rdcForNavigations off again, but it crossed my mind 🙃

The current code in the repo is deployed to https://vercel-rdc-deep-dive-cma0huu9z-rikinsearchofas-projects.vercel.app/en/static-page .