Not possible to create class assignment when educationClass created via Graph

I created 2 educationClass:

• educationClass with description Test100 created via Microsoft Graph
• educationClass with the description Test created by the Teams app.

The educationclass Test100 is created using a POST to https://graph.microsoft.com/V1.0/education/classes with the following JSON object

{
  "displayName": "Test100",
  "description": "Test100",
  "externalId": "3099",
  "mailNickName": "Test100-3099"
}

Teachers are added using a POST to
https://graph.microsoft.com/V1.0/education/classes/ID-Education-Class/teachers/$ref with the following JSON object

{
  "@odata.id": "https://graph.microsoft.com/V1.0/education/users/teacher-ID"
}

Members are added using a POST to
https://graph.microsoft.com/V1.0/education/classes/ID-Education-Class/members/$ref with the following JSON object

{
  "@odata.id": "https://graph.microsoft.com/V1.0/education/users/ID-Member"
}

When I want to assign an assignment in the Teams app, it works fine with the educationClass created via Teams but not for the class created via Graph.

To me, it seems there is something missing in the Group properties for the educationClass created by Graph.

Response from GET GROUP for the class created by the API:

{
  "@odata.context": "https://graph.microsoft.com/V1.0/$metadata#groups/$entity",
  "id": "cd5a64f4-8784-4356-8c04-31deb1aa6849",
  "deletedDateTime": null,
  "classification": null,
  "createdDateTime": "2018-08-06T08:36:28Z",
  "creationOptions": [],
  "description": "Test100",
  "displayName": "Test100",
  "groupTypes": ["Unified"],
  "mail": "Test100-3099@wisad.be",
  "mailEnabled": true,
  "mailNickname": "Test100-3099",
  "onPremisesLastSyncDateTime": null,
  "onPremisesProvisioningErrors": [],
  "onPremisesSecurityIdentifier": null,
  "onPremisesSyncEnabled": null,
  "preferredDataLocation": null,
  "proxyAddresses": ["smtp:Test100-3099@mydomein", "SMTP:Test100-3099@mydomein"],
  "renewedDateTime": "2018-08-06T08:36:28Z",
  "resourceBehaviorOptions": [],
  "resourceProvisioningOptions": ["Team"],
  "securityEnabled": false,
  "visibility": "HiddenMembership",
  "extension_fe2174665583431c953114ff7268b7b3_Education_SyncSource_SectionId": "3099",
  "extension_fe2174665583431c953114ff7268b7b3_Education_CreatedByUserId": "myuserid",
  "extension_fe2174665583431c953114ff7268b7b3_Education_CreatedByAppId": "MyAppID",
  "extension_fe2174665583431c953114ff7268b7b3_Education_ObjectType": "Section"
}

Response from GET GROUP for the class created in Teams:

{
  "@odata.context": "https://graph.microsoft.com/V1.0/$metadata#groups/$entity",
  "id": "e971cfd4-dc4c-4321-ae51-4d216557bec8",
  "deletedDateTime": null,
  "classification": null,
  "createdDateTime": "2018-08-06T11:56:52Z",
  "creationOptions": ["classAssignments", "ExchangeProvisioningFlags:2509"],
  "description": "Test",
  "displayName": "Test",
  "groupTypes": ["Unified"],
  "mail": "Test92@mydomain",
  "mailEnabled": true,
  "mailNickname": "Test92",
  "onPremisesLastSyncDateTime": null,
  "onPremisesProvisioningErrors": [],
  "onPremisesSecurityIdentifier": null,
  "onPremisesSyncEnabled": null,
  "preferredDataLocation": null,
  "proxyAddresses": ["smtp:Test92@mydomein.be", "SMTP:Test92@mydomain.be"],
  "renewedDateTime": "2018-08-06T11:56:52Z",
  "resourceBehaviorOptions": [
    "HideGroupInOutlook",
    "WelcomeEmailDisabled",
    "ConnectorsDisabled",
    "SubscribeNewGroupMembers"
  ],
  "resourceProvisioningOptions": [],
  "securityEnabled": false,
  "visibility": "HiddenMembership",
  "extension_fe2174665583431c953114ff7268b7b3_Education_ObjectType": "Section"
}

Notice that the creationOptions and resourceBehaviorOptions of the two Groups are different.

When I try to add a new assignment to education classes created by the GRAPH API, i get the following message saying: "Education class is being setup"

It is necessary to the send the Term startdate and enddate.

"term":{  
      "displayName":"Term2",
      "externalID":"2",
      "startDate":"2017-09-01",
      "endDate":"2019-08-31"
   }