totp - Yubikey TOTP 生成返回错误代码

Question

我正在尝试从我的 YubiKey 5 NFC 获取当前的 OATH TOTP 代码：

Code otpCode = oathSession.CalculateCredential(myCredential);

不知何故，返回的值与 Yubico Authenticator 应用程序中显示的当前值不同。

using (var oathSession = new OathSession(_yubiKeyToUse))
{
   var myCredential = new Credential
   {
       Issuer = "ACME Inc.",
       AccountName = "Software Development",
       Type = CredentialType.Totp,
       Period = CredentialPeriod.Period30,
       Digits = 6,
       Secret = "HXDMVJECJJWSRB3HWIZR4IFUGFTMXBOZ",
       RequiresTouch = false,
       Algorithm = HashAlgorithm.Sha1
    };

    oathSession.AddCredential(myCredential);
}

什么解释了 TOTP 代码之间的区别？