Quarkus Multipart not working for multi layer applications

[git4rputuval]

We have an export-import microservice design that exports and imports data, one microservice component per family of entities.
This microservice design imports & exports using rest reactive design. And it works perfectly without any issues.

Requirement
But now we have a different requirement. We have a module that provides the user a page to select the list of microservices that needs to be exported and/or imported. After selecting multiple microservices and clicking on "Export" button, a zip file will be generated that contains the exported file of all the microservices selected on the page.

Design
Since all the components already have the export import function, all I have to do is created a separate service that will do the following.

• Take a request that comprises the selected component names.
• Iterate through the component names, and build a Unijoin list to call the export import function of all the microservices in parallel.
  UniJoin.Builder<CommonAccountTypeXMLDto> builder = Uni.join().builder(); builder.joinAll().andFailFast();
• Collect the files into a zip file, and return the zip file.

Issue
The service uses Rest Reactive Client to connect to the individual microservices. So I use the 'Rest Reactive Client with Multipart' approach. But it gives an error.
022-02-25 16:13:11,174 ERROR [org.jbo.res.rea.com.cor.AbstractResteasyReactiveContext] (executor-thread-0) Request failed: javax.ws.rs.ProcessingException: Response could not be mapped to type class com.company.services.exim.client.DownloadFormData

Sample
For the sake of simplicity, I am attaching a single project that contains a server project and a client project.

• Server package returns a multipart object when export is clicked.
• Client package contains the Rest Reactive Client to call the server project.

Also attached is the error text. You can run the project and reproduce the same error. Use postman to call the function.

Please help find the actual cause of the error. Thanks!
raj-quarkus-multipart.zip
Error.txt
.