DataFormat.Error: We couldn't Convert to Number - But it's all Text and I haven't changed type

There are some steps and the use case requires merged queries. The initial import Transform File:

let
    Source = Csv.Document(Parameter2,[Delimiter=";", Columns=33, Encoding=1252, QuoteStyle=QuoteStyle.None]),
    #"Promoted Headers" = Table.PromoteHeaders(Source, [PromoteAllScalars=true]),
    #"Changed Type" = Table.TransformColumnTypes(#"Promoted Headers",{{"SAMPLE COLUMN", type text}, {"SAMPLE COLUMN", type text}, {"SAMPLE COLUMN", type text}, {"SAMPLE COLUMN", type text}, {"SAMPLE COLUMN", type text}, {"SAMPLE COLUMN", type text}, {"SAMPLE COLUMN", type text}, {"SAMPLE COLUMN", type text}, {"SAMPLE COLUMN", type text}, {"SAMPLE COLUMN", type text}, {"SAMPLE COLUMN", type text}, {"SAMPLE COLUMN", type text}, {"SAMPLE COLUMN", type text}, {"SAMPLE COLUMN", type text}, {"SAMPLE COLUMN", type text}, {"SAMPLE COLUMN", type text}, {"SAMPLE COLUMN", type text}, {"SAMPLE COLUMN", type text}, {"SAMPLE COLUMN", type text}, {"SAMPLE COLUMN", type text}, {"SAMPLE COLUMN", type datetime}, {"SAMPLE COLUMN", type datetime}, {"ERROR GENERATING COLUMN", type text}, {"SAMPLE COLUMN", type text}, {"SAMPLE COLUMN", type text}, {"SAMPLE COLUMN", type text}, {"SAMPLE COLUMN", type text}, {"SAMPLE COLUMN", type text}, {"SAMPLE COLUMN", type text}, {"SAMPLE COLUMN", type text}, {"SAMPLE COLUMN", type text}, {"SAMPLE COLUMN", type text}, {"SAMPLE COLUMN", type text}})
in
    #"Changed Type"

Then the Query on the same data:

let
    Source = SharePoint.Files("https://Source.sharepoint.com/teams/GO365_SourceSite", [ApiVersion = 15]),
    #"Filtered Rows" = Table.SelectRows(Source, each Text.Contains([Folder Path], "Filter Value") and not Text.Contains([Folder Path], "Filter Value")),
    #"Filtered Hidden Files1" = Table.SelectRows(#"Filtered Rows", each [Attributes]?[Hidden]? <> true),
    #"Invoke Custom Function1" = Table.AddColumn(#"Filtered Hidden Files1", "Transform File (2)", each #"Transform File (2)"([Content])),
    #"Renamed Columns1" = Table.RenameColumns(#"Invoke Custom Function1", {"Name", "Source.Name"}),
    #"Removed Other Columns1" = Table.SelectColumns(#"Renamed Columns1", {"Source.Name", "Transform File (2)"}),
    #"Expanded Table Column1" = Table.ExpandTableColumn(#"Removed Other Columns1", "Transform File (2)", Table.ColumnNames(#"Transform File (2)"(#"Sample File (2)"))),
    #"Duplicated Column" = Table.DuplicateColumn(#"Expanded Table Column1", "SAMPLE COLUMN", "SAMPLE COLUMN - Copy"),
    #"Duplicated Column1" = Table.DuplicateColumn(#"Duplicated Column", "SAMPLE COLUMN1", "SAMPLE COLUMN1 - Copy"),
    #"Merged Columns" = Table.CombineColumns(#"Duplicated Column1",{"SAMPLE COLUMN - Copy", "SAMPLE COLUMN1 - Copy"},Combiner.CombineTextByDelimiter(" ", QuoteStyle.None),"ID"),
    #"Changed Type" = Table.TransformColumnTypes(#"Merged Columns",{{"ERROR GENERATING COLUMN", type text}})
in
    #"Changed Type"

Then the output query (The error occurs at #"Filtered Rows" step):

let
    Source = Table.NestedJoin(#"Client List", {"IDENTIFIERA"}, #"Status", {"IDENTIFIERB"}, "Status", JoinKind.LeftOuter),
    #"Expanded Status" = Table.ExpandTableColumn(Source, "Status", {"Code", "SAMPLE COLUMN", "SAMPLE COLUMN", "SAMPLE COLUMN", "SAMPLE COLUMN"}, {"Status.Code", "Status.SAMPLE COLUMN", "Status.SAMPLE COLUMN", "Status.SAMPLE COLUMN", "Status.SAMPLE COLUMN"}),
    #"Duplicated Column" = Table.DuplicateColumn(#"Expanded Status", "Account", "Account - Copy"),
    #"Duplicated Column1" = Table.DuplicateColumn(#"Duplicated Column", "Status.SAMPLE COLUMN", "Status.SAMPLE COLUMN - Copy"),
    #"Merged Columns" = Table.CombineColumns(#"Duplicated Column1",{"Account - Copy", "Status.SAMPLE COLUMN - Copy"},Combiner.CombineTextByDelimiter(" ", QuoteStyle.None),"ID"),
    #"Merged Queries" = Table.NestedJoin(#"Merged Columns", {"Status.SAMPLE COLUMN"}, #"QUERY HFA", {"SAMPLE COLUMN"}, "SAMPLE COLUMN HFA", JoinKind.LeftOuter),
    #"Expanded HFA" = Table.ExpandTableColumn(#"Merged Queries", "SAMPLE COLUMN HFA", {"SAMPLE COLUMN", "SAMPLE COLUMN TYPE"}, {"HFA.SAMPLE COLUMN", "HFA.SAMPLE COLUMN"}),
    #"Merged Queries1" = Table.NestedJoin(#"Expanded HFA", {"HFA.SAMPLE COLUMN"}, #"ERROR QUERY", {"SAMPLE COLUMN"}, "ERROR QUERY", JoinKind.LeftOuter),
    #"Expanded ERROR QUERY" = Table.ExpandTableColumn(#"Merged Queries1", "ERROR QUERY", {"SAMPLE COLUMN", "ERROR GENERATING COLUMN"}, {"ERROR QUERY.SAMPLE COLUMN", "ERROR QUERY.ERROR GENERATING COLUMN"}),
    #"Added Conditional Column" = Table.AddColumn(#"Expanded ERROR QUERY", "Match Check", each if [ERROR QUERY.ERROR GENERATING COLUMN] = null then "No" else if [ERROR QUERY.ERROR GENERATING COLUMN] = "" then "No" else if [Account] = [ERROR QUERY.ERROR GENERATING COLUMN] then "Yes" else "No"),
    #"Filtered Rows" = Table.SelectRows(#"Added Conditional Column", each ([Match] = "Yes")),
    #"Merged Queries2" = Table.NestedJoin(#"Filtered Rows", {"Status.Code"}, OTHER QUERY, {"Code"}, "OTHER QUERY", JoinKind.LeftOuter),
    #"Expanded OTHER QUERY" = Table.ExpandTableColumn(#"Merged Queries2", "OTHER QUERY", {"SAMPLE COLUMN", "SAMPLE COLUMN", "SAMPLE COLUMN", "SAMPLE COLUMN", "SAMPLE COLUMN", "SAMPLE COLUMN", "SAMPLE COLUMN"}, {"OTHER QUERY.SAMPLE COLUMN", "OTHER QUERY.SAMPLE COLUMN", "OTHER QUERY.SAMPLE COLUMN", "OTHER QUERY.SAMPLE COLUMN", "OTHER QUERY.SAMPLE COLUMN", "OTHER QUERY.SAMPLE COLUMN", "OTHER QUERY.SAMPLE COLUMN"}),
    #"Added Conditional Column1" = Table.AddColumn(#"Expanded OTHER QUERY", "Direction Match", each if [Direction] = [#"OTHER QUERY.SAMPLE COLUMN"] then "Yes" else null),
    #"Filtered Rows1" = Table.SelectRows(#"Added Conditional Column1", each [Direction Match] <> null and [Direction Match] <> "")
in
    #"Filtered Rows1"

I've named the column as ERROR GENERATING COLUMN throughout. The error occurs when the related conditional column is filtered. I cannot see why Power Query is trying to convert this data from the error column to a number at this point?