- (void)applyConfiguration:(NEHotspotConfiguration *)configuration error is nil when connect failed

NEHotspotConfiguration *config = [[NEHotspotConfiguration alloc] initWithSSID:[NSString stringWithFormat:@"SomeSSID"];
[[NEHotspotConfigurationManager sharedManager] applyConfiguration:config completionHandler:^(NSError * _Nullable error) {
}];

This function does not giving an error(error is nil) when it failed to connect the given ssid, but an alert message is presented "Unable to join network SomeSSID"

How do we know as developer if the app is connect to the SSID.

Thanks ahead.