sim_info sometimes is unworkable

[kenyu-yu]

Hi,
my test device : iphone 11 / iOS 14.3
when I called sim_info in flutter to get sim info, sometimes I got the null result. Once I retry again, it is workable to get correct sim info. It is so strange.
here is my source code
=============source code =========================
Future getSimInfo() async {
print("starting getSimInfo");
String allowsVOIP = await SimInfo.getAllowsVOIP;
String carrierName = await SimInfo.getCarrierName;
String isoCountryCode = await SimInfo.getIsoCountryCode;
String mobileCountryCode = await SimInfo.getMobileCountryCode;
String mobileNetworkCode = await SimInfo.getMobileNetworkCode;

print("mobileCountryCode:$mobileCountryCode, mobileNetworkCode:$mobileNetworkCode");

setState(() {
  _allowsVOIP = allowsVOIP;
  _carrierName = carrierName;
  _isoCountryCode = isoCountryCode;
  _mobileCountryCode = mobileCountryCode;
  _mobileNetworkCode = mobileNetworkCode;

});

}

[kenyu-yu]

I got the error description as the below.
How can I solve the issue?

2021-01-14 18:05:23.674190+0800 Runner[4201:1355438] [Client] Updating selectors after delegate removal failed with: Error Domain=NSCocoaErrorDomain Code=4099 "The connection to service on pid 91 named com.apple.commcenter.coretelephony.xpc was invalidated from this process." UserInfo={NSDebugDescription=The connection to service on pid 91 named com.apple.commcenter.coretelephony.xpc was invalidated from this process.}

[Vipul-Garg16]

I also getting this same problem in ios OS 14.7.1