Allocations instruments shows leaks, but no way to fix

I wrote simple NSMutableData test project. I profiled with allocations instruments. It shows alloc1() total bytes are 55MB. But alloc1() only called once and alloced byte should be 1MB. I cannot find the reason of 55MB allocation in alloc1()

Replace this code with fresh macOS App project on Xcode13.

#import "ViewController.h"
@implementation ViewController {
    NSTimer *mTimer;
    NSMutableData *mData1;
    NSMutableData *mData2;
}
- (void)viewDidLoad {
    [super viewDidLoad];
    mData1 = nil;
    mData2 = nil;
    mTimer = [NSTimer scheduledTimerWithTimeInterval:1.0 target:self
            selector:@selector(timer_cb) userInfo:nil repeats:YES];
}
- (void) timer_cb {
    if (mData1 == nil) {
        [self alloc1];
    }
    if (mData2 == nil) {
        [self alloc2];
    }
    [self copy1];
}
- (void) alloc1 {
    NSLog(@"alloc1");
    mData1 = [NSMutableData dataWithCapacity:1024*1024];
}
- (void) alloc2 {
    NSLog(@"alloc2");
    mData2 = [NSMutableData dataWithCapacity:1024*1024];
    [mData2 resetBytesInRange:NSMakeRange(0, 1024*1024)];
}
- (void) copy1 {
    [mData1 replaceBytesInRange:NSMakeRange(0, 1024*1024) withBytes:mData2.bytes];
}
@end