apm-agent-java: WebFlux - transaction has status code 200 where it should be 500

1. spring version 2.2.6 webflux, netty

    @Operation(
        summary = "상품 이미지 검색", description = "상품 이미지 검색 api", responses = {
            @ApiResponse(responseCode = "200", description = "상품 이미지 검색 성공", content = @Content(schema = @Schema(implementation = GoodsDTOV1.ImageResponse.class))),
            @ApiResponse(responseCode = "404", description = "상품 이미지 검색 실패", content = @Content(schema = @Schema(implementation = GoodsDTOV1.ImageResponse.class)))
        }
    )
    @GetMapping("/goods")
    @ReactorCacheables(cacheNames = CacheNameConstant.GOODS_IMAGE_LIST, key = "getCacheKey(#method)")
    public Mono<ResponseDTOV2> getGoodsList(@ParameterObject @ModelAttribute @Valid GoodsDTOV1.Search goods) {
        return goodsService.getGoodsList(goods.getUrl(), ImageSearchTypeEnum.getValue(goods.getImageSearchType()))
            .flatMap(goodsImageVO -> {

                final GoodsDTOV1.ImageResponse imageResponse = goodsMapStruct.toDTO(goodsImageVO);

                if (1 == 1) {
                    throw new RuntimeException();
                }

                return Mono.just(
                    ResponseDTOV2.builder().data(imageResponse).build()
                );
            });
    }


Obviously a status 500 internal server error occurred.
In elastic-apm it comes out as 200

    @Operation(
        summary = "상품 이미지 검색", description = "상품 이미지 검색 api", responses = {
            @ApiResponse(responseCode = "200", description = "상품 이미지 검색 성공", content = @Content(schema = @Schema(implementation = GoodsDTOV1.ImageResponse.class))),
            @ApiResponse(responseCode = "404", description = "상품 이미지 검색 실패", content = @Content(schema = @Schema(implementation = GoodsDTOV1.ImageResponse.class)))
        }
    )
    @GetMapping("/goods")
    @ReactorCacheables(cacheNames = CacheNameConstant.GOODS_IMAGE_LIST, key = "getCacheKey(#method)")
    public Mono<ResponseDTOV2> getGoodsList(@ParameterObject @ModelAttribute @Valid GoodsDTOV1.Search goods) {

         if (1 == 1) {
                throw new RuntimeException();
         }

        return goodsService.getGoodsList(goods.getUrl(), ImageSearchTypeEnum.getValue(goods.getImageSearchType()))
            .flatMap(goodsImageVO -> {

                final GoodsDTOV1.ImageResponse imageResponse = goodsMapStruct.toDTO(goodsImageVO);



                return Mono.just(
                    ResponseDTOV2.builder().data(imageResponse).build()
                );
            });
    }

If the exception is outside of mono, it is exposed normally, but if an error occurs inside mono, it does not work properly.

404 is normal