Inconsistent behaviour of revalidatePath between local and Vercel

[damianfrizzi]

Link to the code that reproduces this issue

https://github.com/damianfrizzi/next-revalidate-bug

To Reproduce

• Go to https://next-revalidate-bug.vercel.app and note the number at the top
• Navigate to "Go to some page" and note the number at the top
• Go back to homepage and click "Invalidate German" and refresh page
• Number correctly changes on the homepage
• BUT number also changes on the "/somePage" route. This shouldn't happen

Current vs. Expected behavior

revalidatePath behaves correctly when using bun build && bun start on my local machine. I.e., invalidating the homepage doesn't invalidate any other (sub) pages.

When deployed to Vercel, invalidating the homepage also invalidates other (sub) pages.

Provide environment information

Operating System:
  Platform: darwin
  Arch: arm64
  Version: Darwin Kernel Version 24.0.0: Tue Sep 24 23:39:07 PDT 2024; root:xnu-11215.1.12~1/RELEASE_ARM64_T6000
  Available memory (MB): 32768
  Available CPU cores: 10
Binaries:
  Node: 20.17.0
  npm: 10.8.2
  Yarn: 1.22.19
  pnpm: N/A
Relevant Packages:
  next: 15.0.3 // Latest available version is detected (15.0.3).
  eslint-config-next: 15.0.3
  react: 19.0.0-rc-66855b96-20241106
  react-dom: 19.0.0-rc-66855b96-20241106
  typescript: 5.6.3
Next.js Config:
  output: N/A

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

Internationalization (i18n), Middleware, Runtime

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

Vercel (Deployed)

Additional context

I'm using trailingSlash: true in my next.config. I suspect that there is an error in connection with this configuration.