CosmosDB database with Mongodb api, CosmosDB connector supported?

Hello, I have a CosmosDB database with MongoDB api setup and trying to connect with Power BI CosmosDB connector.

The connection is successful but the data looks weird. Instead of my usual column names I have alot of $t $v columns.

For example:

{
    "$t": 3,
    "$v": {
      "_id": {
        "$t": 7,
        "$v": "40008"
      },
      "userId": {
        "$t": 5,
        "$v": "xyz"
      }

}

Can anyone from Microsoft tell me if this setup is supported?