Given a context like:

"@context": {
    "@vocab": "https://example.org",
    "@type": {
      "@container": "@set"
    }
}

When using the serialization for framing, the term's definition value for @id is used and added to the context resulting in:

"@context": {
    "@vocab": "https://example.org",
    "@type": {
      "@id": "type"
      "@container": "@set"
    }
}

This goes against the de-serialization rules:

The type's @id definition was added in change: 673dac2 and seems like it was tested with compact serialization.

Serialization references: