checkmarx medium severity: May unintentionally allow setting the value of method in the object

Question

I am getting below medium vulnerability highlighted in checkmarx:

The rModificationRequest at r-config\com\mycompapi\RController.java in line# may unintentionally allow setting the value of saveAndFlush in modifyR, in the object r-config\com\mycompservices\RService.java at line#.

@RestController
@RequestMapping(path = "/api/v1/r", produces = MediaType.APPLICATION_JSON_VALUE)
@Api(tags = "R", value = "Endpoints for managing all the operations related to r")
@Slf4j
@Validated
public class RController {
    private final RService rService;
    private final ModelMapper modelMapper;
    
    @Autowired
    public RController(final RService rService,
                               final ModelMapper modelMapper) {
        this.rService = rService;
        this.modelMapper = modelMapper;
    }

    @ApiOperation(value = "Modify r information", nickname = "modifyR")
    @PatchMapping
    @ResponseStatus(HttpStatus.OK)
    public RResponse modifyRInfo(
            @RequestParam(name = "r-name") @NotBlank
            @Size(max = 256, message = "r name should have less than or equals to {max} characters") final String rName,
            @Valid @RequestBody RModificationRequest rModificationRequest) {

        final RModificationDto rModificationDto = modelMapper.map(rModificationRequest,
                                                                                  RModificationDto.class);

        final R r = rService.modifyR(rName, rModificationDto);

        return modelMapper.map(r, RResponse.class);
    }
}

@Service
public class RService {

    private final RRepository rRepository;

    @Autowired
    public RService(final RRepository rRepository) {

        this.rRepository = rRepository;
    }
    
    @Transactional
    @PublishNotification(operationType = OperationType.MODIFY)
    public R modifyR(final String rName, final RModificationDto rModificationDto) {

        final R r = findByRName(rName);
        final R modifiedR = RServiceHelper.getModifiedR(r, rModificationDto);
        rRepository.saveAndFlush(modifiedR);
        return modifiedR;
    }

What to do here or is it false positive? I don't see any comment also of what to do like sonar-cube scans have or may be its somewhere I don't know - I am new to checkmarx.