InjectionIII: found objects does not initialize

Hi, found a case that some object does not initialize as expect. The demo code is below.

1. change the DemoViewController code to trigger recompile the DemoViewController
2. reenter DemoViewController, found the label is null, but the contentLabel is OK

@interface DemoViewController ()

@property (nonatomic, strong) UILabel *contentLabel;

@end

@implementation DemoViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    
    UILabel *label = [[UILabel alloc] init];
    label.frame = CGRectMake(0, 200, 100, 100);
    label.backgroundColor = [UIColor whiteColor];
    label.text = @"label";
    NSLog(@"label = %@", label); // label is null, not initialize
    [self.view addSubview:label];

    [self.view addSubview:self.contentLabel]; 
    NSLog(@"label = %@", self.contentLabel); // contentLabel is null, not initialize
}

- (UILabel *)contentLabel {
    if (!_contentLabel) {
        _contentLabel = [UILabel new];
        _contentLabel.frame = CGRectMake(100, 100, 100, 100);
        _contentLabel.backgroundColor = [UIColor whiteColor];
        _contentLabel.text = @"123";
    }
    return _contentLabel;
}

@end