I've met problem with enums as params of underlying service endpoints. For example underlying service have endpoint ~/api/v1/books that accepts query params:

• editions (array of enum: EditionType)
• cover (enum: CoverType)

Swaggelot (swagger of Ocelot gateway) configured to reach that service endpoint. In Swagger UI we will see that editions accepts array with possible values from EditionType enum - that is valid behaviour. But cover accepts any string, ignoring related enum values (UI even doesn't suggest you any enum value) - that is invalid behaviour.

So actually it look like for some reason Swaggelot lost relation between enum and parameter, in case of parameter having enum type.