Grouping by consecutive data in column

Consider the example table...

You can end up with the following...

Using the code...

let
    Source = 
    Table.FromRows(Json.Document(Binary.Decompress(Binary.FromText("Zc67CsAgDIXhV5HMgiaN160tdO4uvv9r1KlwzHAyffxkDOKgQaKoY+5JydN53eu+a0zTbyD94FkTCzKAw4ICQC2o8EOyoDlI5E1IjxESxQKGQrVAADSa8wM=", BinaryEncoding.Base64), Compression.Deflate)), let _t = ((type nullable text) meta [Serialized.Text = true]) in type table [Date = _t, Code = _t, Result = _t, Index = _t]),
    #"Changed Type" = 
    Table.TransformColumnTypes(Source,{{"Date", type datetime}, {"Code", type text}, {"Result", type text}}),
    #"Grouped Rows" = 
    Table.Group(#"Changed Type", {"Result"}, {{"Count", each Table.RowCount(_), Int64.Type}, {"Records", each _, type table [Date=nullable datetime, Code=nullable text, Result=nullable text]}},GroupKind.Local),
    #"Group Failed" = 
    Table.AddIndexColumn(Table.SelectRows(#"Grouped Rows", each [Result] = "F" and [Count] <> 1), "Group", 1, 1),
    #"Removed Columns" =
    Table.RemoveColumns(#"Group Failed",{"Result", "Count"}),
    #"Expanded Records" = 
    Table.ExpandTableColumn(#"Removed Columns", "Records", {"Date", "Code", "Result", "Index"}, {"Date", "Code", "Result", "Index"}),
    #"Non Consecutive" = 
    Table.SelectRows(#"Grouped Rows", each [Result] <> "F" or [Count] = 1),
    #"Removed Columns1" = 
    Table.RemoveColumns(#"Non Consecutive",{"Result", "Count"}),
    #"Expanded Records1" = 
    Table.ExpandTableColumn(#"Removed Columns1", "Records", {"Date", "Code", "Result", "Index"}, {"Date", "Code", "Result", "Index"}),
    #"Combine Tables" = 
    Table.Combine({#"Expanded Records1", #"Expanded Records"}),
    #"Sorted Rows" = 
    Table.Sort(#"Combine Tables",{{"Index", Order.Ascending}})
in
    #"Sorted Rows"

The key is the GroupKind.Local in the Table.Group step.

Hopefully this helps.