Kotlin 使用 clear() 删除 EncryptedSharedPreferences 不起作用

I use the EncryptedSharedPreferences from the androidx.security:security-crypto:1.0.0-alpha02 lib to store some Tokens. If i use prefs.edit().remove("token")).apply() or prefs.edit().remove("token")).commit() the token is removed. But if i try to clear the prefs at once with the clear() method nothing happens.

This call: prefs.edit().clear().commit() even returns false.

I get the EncryptedSharedPreferences by using this method:

    private fun getPrefs(): SharedPreferences {

    val masterKeyAlias = MasterKeys.getOrCreate(MasterKeys.AES256_GCM_SPEC)
    return EncryptedSharedPreferences.create(
            "myPrefs",
            masterKeyAlias,
            context,
            EncryptedSharedPreferences.PrefKeyEncryptionScheme.AES256_SIV,
            EncryptedSharedPreferences.PrefValueEncryptionScheme.AES256_GCM

    )
}

Do i have to clear the EncryptedSharedPreferences in some other way?

The documentation says (https://developer.android.com/reference/androidx/security/crypto/EncryptedSharedPreferences) :

//像往常一样使用共享首选项和编辑器

Update 07.02.2020 I created a bug ticket in the google bugtracker (https://issuetracker.google.com/issues/138314232) but they wont fix it...