Request Preferences are erroneously being deleted

{
    "users": [
        {
            "username": "md331@duke.edu",
            "externalSystemId": "12345",
            "active": true,
            "patronGroup": "Staff"
        }
    ],
    "deactivateMissingUsers": false,
    "totalRecords": 1,
    "updateOnlyPresentFields": true
}

        {
            "username": "md331@duke.edu",
            "externalSystemId": "12345",
            "errorMessage": "Failed to delete user preference.Failed to decode:Cannot construct instance of `java.util.LinkedHashMap` (although at least one Creator exists): no String-argument constructor/factory method to deserialize from String value ('159c0f18-85ba-417e-a705-7306adc6416d')\n at [Source: (String)\"\"159c0f18-85ba-417e-a705-7306adc6416d\"\"; line: 1, column: 1]"
        }