I try to use springfox to generate API documentation, but when I set the Http response body to a generic type, a problem occurs and it cannot be parsed correctly

I am using the following version of springfox

<dependency>
    <groupId>io.springfox</groupId>
    <artifactId>springfox-boot-starter</artifactId>
    <version>3.0.0</version>
</dependency>

I wrote a class with generics and tried to return it via http response, with the code like this

// wrapper class
@Data
public class TestResp<T> {
    private T data;
}

// data
@Data
public class TestData {
    private String testMsg;
   
    public TestData(String testMsg) { this.testMsg = testMsg; }
}

// controller 

@RestController
public class TestController {

    @GetMapping("test")
    @ApiOperation("test")
    private TestResp<TestData> testResp() {
        return new TestResp<>(new TestData("test"));
    }
}

So far it looks fine, but! When I tried to open swagger-ui, a strange scene occurred:

{
    "schemas": {
        "TestData": {
            "title": "TestData",
            "type": "object",
            "properties": {
                "testMsg": {
                    "type": "string"
                }
            }
        },
        "TestResp«TestData»": {
            "title": "TestResp«TestData»",
            "type": "object",
            "properties": {
                "data": {
                    "type": "object"    // Why is the type of data not TestData but object?
                }
            }
        }
    }
}

I think it should be able to display generic types normally. I remember it was possible before, but I don’t know why it’s like this now.