Once I was assigned the "Application Developer" Azure AD role I could no longer issue requests where I set myself as owner of a group when creating it. I consider this to be broken as implicit behavior based on role assignment affect the format of my requests to the Graph API!

Failing request:
{
"displayName": "My group",
"mailEnabled": false,
"mailNickname": "undefined",
"securityEnabled": true,
"owners@odata.bind": [

&quot;<a rel="nofollow noreferrer" href="https://graph.microsoft.com/v1.0/users/">https://graph.microsoft.com/v1.0/users/</a>&lt;id of myself&gt;&quot;

]
}

Response:
{

"error": {

    "code": "Request_BadRequest",

    "message": "Request contains a property with duplicate values.",

    "innerError": {

        "request-id": "aae9881c-570e-4443-9ce7-a4ca87889d9e",

        "date": "2019-10-02T13:06:59"

    }

}

}

Successful request:
{
"displayName": "My group",
"mailEnabled": false,
"mailNickname": "undefined",
"securityEnabled": true
}

This time the group was created and I was set as owner anyway based on my "Application Developer" role.