Spring WebFlux HATEOAS No Encoder for EntityModel with preset Content-Type 'null'

Affects: org.springframework.boot:spring-boot-starter-parent:2.5.2

Currently also an open stackoverflow question.

While trying to expose and consume an endpoint which produces application/x-ndjson and returns a HAL-JSON some kind of integration is missing, I'm able to return and de-serialize a Mono<List> of HAL-JSON, but not a Flux.

(...)
	<parent>
		<groupId>org.springframework.boot</groupId>
		<artifactId>spring-boot-starter-parent</artifactId>
		<version>2.5.2</version>
		<relativePath />
	</parent>
	<dependencies>
		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-webflux</artifactId>
		</dependency>
		(...)
	<dependencies>
(...)

public class Pojo {
	private Integer id;
	private String name;

	public Pojo(Integer id, String name) {
		this.id=id; this.name=name;
	}

	public Integer getId() { return id; }
	public String getName() { return name; }
}

@RestController
@RequestMapping()
public class PojoResource {
	Flux<Pojo> getPojos() {
		return Flux.just(new Pojo(1, "alpha"), new Pojo(2, "beta"), new Pojo(3, "gamma"));
	}
	
	@GetMapping(value="/pojoA", produces = MediaType.APPLICATION_NDJSON_VALUE)
	public Flux<Pojo> getAllPojosAsStream() {
		return getPojos();
	}
	
	@GetMapping("/pojoB")
	public Mono<List<EntityModel<Pojo>>> getAllPojosAsHAL() {
		return getAllPojosAsHALStream().collectList();
	}

	@GetMapping(value="/pojoC", produces = MediaType.APPLICATION_NDJSON_VALUE)
	public Flux<EntityModel<Pojo>> getAllPojosAsHALStream() {
		return getPojos().map(p -> EntityModel.of(p));
	}
}

Calling for Flux of Pojo

curl -X 'GET' 'http://localhost:8080/pojoA' -H 'accept: application/x-ndjson'

Works like a charm:

{"id":1,"name":"alpha"}
{"id":2,"name":"beta"}
{"id":3,"name":"gamma"}

Calling for Mono of List of EntityModel of Pojo

curl -X 'GET' 'http://localhost:8080/pojoB' -H 'accept: */*'

Another gem:

[
  {
    "id": 1,
    "name": "alpha",
    "links": []
  },
  {
    "id": 2,
    "name": "beta",
    "links": []
  },
  {
    "id": 3,
    "name": "gamma",
    "links": []
  }
]

But calling for Flux of EntityModel of Pojo

curl -X 'GET' 'http://localhost:8080/pojoC' -H 'accept: application/x-ndjson'

Fails with an exception:

org.springframework.http.converter.HttpMessageNotWritableException: No Encoder for [org.springframework.hateoas.EntityModel<my.package.Pojo>] with preset Content-Type 'null'
(Full stacktrace can be provided if needed)

Is this not an intended use case?
If you can provide me a little of info about the jackson encoders perhaps I can contribute with my grain of sand.

Start by running the /pojoC example with a Flux<EntityModel> and the application/x-ndjson Accept header, then compare it with the working /pojoA and /pojoB endpoints. Trace the WebFlux message-writing path for EntityModel and identify the missing encoder integration; done means the streaming HAL response is encoded successfully without the reported exception.