Copy Activity: Copying data from and to Azure Cosmos DB for MongoDB: "The retrieved type of data JObject is not supported yet"

I am using Azure Data Factory `Copy Activity` to copy a collection from and to `Azure Cosmos DB for MongoDB`.

The data that is getting saved in the `from` collection, we don't have control over and is managed by a third party.

When copying the data over, I am getting the following error for this particular document.

Error:
```
"The retrieved type of data JObject is not supported yet.
Please either remove the targeted column 'formDefaults' or enable skip incompatible row to skip the issue rows."
```
Document:
```
{
...
"formDefaults": {
"revisions": "original"
},
...
}
```
For all other documents in this particular collection, `formDefaults` is `null`. Only for this document, it has an object value. But still, why wouldn't it copy the data over?