Posting to the endpoint https://graph.microsoft.com/beta/accessReviews gives HTTP error 500

Question

I can read data from the endpoint, but when I try to post data (in order to create an access review) I always get HTTP error 500 (Internal Server Error).

Is this operation working?

Example of payload:

{
    "displayName": "ORG_SuperDuper X",
    "startDateTime": "2021-03-04T15:46:25+01:00",
    "endDateTime": "9999-12-31T23:59:59+00:00",
    "reviewedEntity": {
        "id": "30552695-062d-4eed-aebb-a21df20414ad"
    },
    "reviewerType": "delegated",
    "businessFlowTemplateId": "6e4f3d20-c5c3-407f-9695-8460952bcc68",
    "description": "Access Review of ORG_SuperDuper X",
    "reviewers": [
        {
            "id": "137be449-6504-46d5-8556-85c31938eef6"
        }
    ],
    "settings": {
        "remindersEnabled": true,
        "mailNotificationsEnabled": true,
        "justificationRequiredOnApproval": false,
        "recurrenceSettings": {
            "recurrenceType": "halfyearly",
            "recurrenceEndType": "never",
            "recurrenceCount": 0
        },
        "autoApplyReviewResultsEnabled": false
    }
}