为什么SCDynamicStoreSetValue不存储值？

Question

在越狱的iOS环境（11.3.1）中运行此代码时，不会存储新的DNS值：

SCDynamicStoreRef store = SCDynamicStoreCreate(kCFAllocatorDefault, CFSTR("init_by_defaults_systemconfiguration"), NULL, NULL);
CFStringRef key = CFSTR("State:/Network/Global/DNS");
CFDictionaryRef dnsDict = (CFDictionaryRef)SCDynamicStoreCopyValue(store, key);

//Create new values
CFMutableDictionaryRef newdnsDict = CFDictionaryCreateMutableCopy(NULL,0,dnsDict);

CFMutableArrayRef newdnsServerAddresses = CFArrayCreateMutable(NULL,0,NULL);
CFArrayAppendValue(newdnsServerAddresses, CFSTR("8.8.8.8"));
CFArrayAppendValue(newdnsServerAddresses, CFSTR("8.8.4.4"));

CFDictionarySetValue(newdnsDict, CFSTR("ServerAddresses"), newdnsServerAddresses);

SCDynamicStoreSetValue(store, key, newdnsDict);

//Clean up
CFRelease(store);
CFRelease(key);
CFRelease(dnsDict);
CFRelease(newdnsServerAddresses);
CFRelease(newdnsDict);

我知道自运行以来就没有存储该值

scutil --dns

我看不到新的DNS值。