Values changing to Null for no obvious reason

[baitmaster]

Good afternoon all

I have a Power BI Query that's extracting a load of data from a SQL Server database. I then perform several steps in Power Query, but at some point, for no obvious reason (that I can see), most of my numbers turn to NULL.

The numbers are different currency versions of the same thing, all stored on the server. Advanced Editor shows the following

let
    Source = Sql.Databases("xxxx"),
    #"xxxx" = Source{[Name="xxxx"]}[Data],
    dbo_FactAccountsReceivable = #"xxxx"{[Schema="dbo",Item="FactAccountsReceivable"]}[Data],
    #"Removed Columns" = Table.RemoveColumns(dbo_FactAccountsReceivable,{"Days to Pay", "Settlement", "Document Number", "Current Status", "ea_Is_Deleted"}),
    #"Filtered Rows" = Table.SelectRows(#"Removed Columns", each true),
    #"Duplicated Column" = Table.DuplicateColumn(#"Filtered Rows", "Voucher", "Voucher - Copy"),
    #"Extracted First Characters" = Table.TransformColumns(#"Duplicated Column", {{"Voucher - Copy", each Text.Start(_, 4), type text}}),
    … ...

I'm fine removing columns and filtering but at the point when I duplicate a column, many of my numbers turn to NULL. The column I'm duplicating is a simple text field and is unrelated to the values. There's no change to the number type, and no update from the database. Why would this happen?

 

[baitmaster]

Solution found. The issue affected all columns with >2 DPs. They were formatted as decimal numbers (should be fine right? no...) but swapping to fixed decimal numbers stopped this bug reoccuring