OpenAPI 2.0/3.x.y - semantic highlighting does not always work for responses

[glowcloud]

Describe the bug you're encountering

Semantic highlighting is buggy for responses, e.g. it does not work when the default response is the last response defined:

When it is gone or defined as the first response:

Sometimes the highlighting will partially work, e.g. in this case the highlighting will work for every response expect for the default one, as well as the 200 key:

To reproduce...

Steps to reproduce the behavior:

1. Go to https://editor-next.swagger.io/
2. Load the OpenAPI 3.0 or 3.1 example
3. Scroll through the definition to see responses for different operations