Collection of Collection is not properly rendered by swagger-ui in quarkus example

Testing strongly typed Collection of Collection with dmn-quarkus-example , swagger-ui doesn't properly render the type (ColOfCol-quarkus.png).

 Interestingly, if I test the same with dmn-springboot-example, I see that a correct swagger.json is generated and I can view it with https://editor.swagger.io/  (ColOfCol-springboot.png).

 So I think the issue exists in swagger-ui in quarkus example (not yet sure whether the issue is swagger-ui itself or our usage).