Link to the code that reproduces this issue

https://github.com/theroot79/my-meta-test-app

To Reproduce

npx create-next-app@latest my-meta-test-app
Need to install the following packages:
create-next-app@15.3.2
Ok to proceed? (y) y

✔ Would you like to use TypeScript? … No / Yes
✔ Would you like to use ESLint? … No / Yes
✔ Would you like to use Tailwind CSS? … No / Yes
✔ Would you like your code inside a src/ directory? … No / Yes
✔ Would you like to use App Router? (recommended) … No / Yes
✔ Would you like to use Turbopack for next dev? … No / Yes
✔ Would you like to customize the import alias (@/* by default)? … No / Yes
✔ What import alias would you like configured? … @/*

Current vs. Expected behavior

Expected behavior:

All tags should render inside , not .

Actual behavior:

On first load, several tags (e.g. description, robots, etc.) appear inside instead of , breaking SEO and causing hydration mismatches.

Provide environment information

npx --no-install next info

Operating System:
  Platform: darwin
  Arch: arm64
  Version: Darwin Kernel Version 24.4.0: Fri Apr 11 18:32:50 PDT 2025; root:xnu-11417.101.15~117/RELEASE_ARM64_T6041
  Available memory (MB): 36864
  Available CPU cores: 14
Binaries:
  Node: 23.11.0
  npm: 10.9.2
  Yarn: 1.22.22
  pnpm: 10.11.0
Relevant Packages:
  next: 15.3.2 // Latest available version is detected (15.3.2).
  eslint-config-next: 15.3.2
  react: 19.1.0
  react-dom: 19.1.0
  typescript: 5.8.3
Next.js Config:
  output: N/A

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

Metadata

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

next dev (local)

Additional context