Wrong header output when running `redocly bundle`

[tandiljuan]

Describe the bug

Using my files, when running the bundle (sub) command, the bundled output is not well formed. There is a header that looks like:

X-Location:
  $ref: components.yaml#/components/headers/created_url

But it should look like:

X-Location:
  $ref: '#/components/headers/created_url'

The reference worked on other files, but it failed in the file that was used twice.

I tried to replicate the bug with a simple and small demo without success. That's why I'm sharing the repository where it's failing.

• file: routehub/deliveries.yaml
• line: 216

To Reproduce

1. Clone the repository from: https://github.com/tandiljuan/routehub-openapi/tree/error_bundle
2. npm install
3. npm run bundle-yaml

Expected behavior

X-Location:
  $ref: '#/components/headers/created_url'

Redocly version(s)

2.12.6

Node.js version(s)

• node: 24.9.0
• npm: 11.6.0

OS, environment

Linux