[JAVA] api Object used in api's body instead of actual type

Description

the api body parameter is of type Object instead of the required type , even though the required type is being generated correctly

Swagger-codegen version

3.0.5 - had this issue since moving to open api from swagger

Swagger declaration file content or url

https://gist.github.com/asafbennatan/313fd8ff8c042f7047a2cdef264b3118

Command line used for generation

java -jar \modules\swagger-codegen-cli\target\swagger-codegen-cli.jar generate -i C:\Users\asaf\IdeaProjects\swagger-downloader\target\openapi.json -l java -o samples\client\petstore\jersey2 --library=jersey2 -DdateLibrary=joda -DhideGenerationTimestamp=true

Steps to reproduce

1.run command above
2. check TenantsApi file , notice the header for the method is:
public Tenant updateTenant(Object body, String authenticationkey) throws ApiException
where it should be:
public Tenant updateTenant(TenantUpdate body, String authenticationkey) throws ApiException

Related issues/PRs

when using typescript generator the issue is the same ( this makes me think the issue is unrelated to specific generator)

generated output:

https://ufile.io/mt986

(will be available for the next 30 days )