SQL Server 2019 - Polybase -> Cosmos DB (MongoDB Mode) Error with dates

I'm new to polybase. I have linked my SQL Serer 2019 to a third parties Azure cosmos and i am able to query data out of my collection. I am getting an error out when i try to query date fields though. In the documents the dates are defined as: "created" : { "$date" : 1579540834768 }, In my external table i have the column defined as [created] DATE, I have tried to create the column as int and nvarchar(128) but the schema detection rejects it each time. (I have tried to create a field created_date but the schema detection also disagrees that this is correct. When I try a query that returns any of the date fields I get this error: Msg 105082, Level 16, State 1, Line 8 105082;Generic ODBC error: [Microsoft][Support] (40460) Fractional data truncated while performing conversion. . OLE DB provider "MSOLEDBSQL" for linked server "(null)" returned message "Unspecified error". Msg 7421, Level 16, State 2, Line 8 Cannot fetch the rowset from OLE DB provider "MSOLEDBSQL" for linked server "(null)". . This happens if i try and exclude null values in my query - even when filtering to specific records where the date is populated (validated using the Azure portal interface) Is there something i should be doing to handle the integer date from the json records; or another type i can use to get my external table to work?