Q&A (please complete the following information)

• OS: Windows
• Browser: chrome
• Version: latest
• Method of installation: From NSwag
• Swagger-UI version: latest
• Swagger/OpenAPI version: OpenAPI 3.0

Content & configuration

This PR, https://github.com/swagger-api/swagger-ui/pull/8579/files, caused a regression for payloads that are not application/octet-stream.

For example, given these Response Headers:

Content-Disposition: attachment; filename=users.csv; filename*=UTF-8''users.csv
Content-Length: 6460682
Content-Type: text/csv

the type of content on this line is string, and therefore content.size === undefined.

Screenshots