Link to the code that reproduces this issue

https://github.com/dincerpece/next-feedback

To Reproduce

1. no-turbopack-build
2. start

Current vs. Expected behavior

When I build without Turbopack and load the page with cache disabled, the fonts are reloaded and rendered out of proportion. I don't know if this is a lag or a css issue.

I made "Slow 4G" to be visible in the video, otherwise it would not be visible, make it "No throttling".

Provide environment information

Operating System:
  Platform: win32
  Arch: x64
  Version: Windows 11 Pro
  Available memory (MB): 32607
  Available CPU cores: 16
Binaries:
  Node: 24.7.0
  npm: 11.1.0
  Yarn: 1.22.22
  pnpm: N/A
Relevant Packages:
  next: 15.5.1-canary.31 // Latest available version is detected (15.5.1-canary.31).
  eslint-config-next: 15.5.1-canary.3
  react: 19.1.0
  react-dom: 19.1.0
  typescript: 5.9.2
Next.js Config:
  output: N/A

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

create-next-app, CSS

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

next build (local), next start (local)

Additional context

I discovered this while testing in Chrome and Lighthouse. I tried to resolve this by minimizing the size of my project and find the problem, but the problem was in the build phase! I'm building normally because turbopack was causing the js files to grow even less. When I created a clean project and checked, this problem disappeared. After starting the build with "build --turbopack", I noticed that my fonts were no longer loading or corrupted, even though they weren't in the cache.