Grouping by three conditions

No. As I said earlier, null, blank/empty, and space are different. Here is the same code but I've replaced your <space> with ""

let
    Source = Table.FromRows(Json.Document(Binary.Decompress(Binary.FromText("jZG7DoJAEEV/ZbK1xczs8lg6Gwtb7QgFRqIkCAmPwr93ARMgA0qyJAS4h3Nn4lhpbdFYY9RBMcO5K4DR3YO7LtUra595+YCsaDL3gBgI3XtGoDBiG2lSyWHJwIlxfeYNfFkyikPUhoEh7dnAfYMGjt1j9/81RhQKCJutEqsAkgCeN0jb1QIuirLAMjqW/18CpQNZOGW3qYQU6I8U2JGz7sjJ+1NOilf1PS/T+i3lKWIpP4dtyuMowV6omXzfmnF1M4th8j+255qwLyHzEezcQU/yVJJ8AA==", BinaryEncoding.Base64), Compression.Deflate)), let _t = ((type nullable text) meta [Serialized.Text = true]) in type table [ID = _t, Date = _t, Status = _t, Result = _t, #"Record last updated" = _t]),
    #"Changed Type" = Table.TransformColumnTypes(Source,{{"Date", type date}, {"Record last updated", type datetime}}),
    #"Replaced Value" = Table.ReplaceValue(#"Changed Type"," ","",Replacer.ReplaceValue,{"Status", "Result"}),
    #"Grouped Rows" = Table.Group(#"Replaced Value", {"ID"}, {{"All Rows", each _, type table [ID=nullable text, Date=nullable date, Status=nullable text, Result=nullable text, Record last updated=nullable datetime]}}),
    #"Added Status" = 
        Table.AddColumn(
            #"Grouped Rows", 
            "Status", 
            each
            Table.Max( 
                Table.FromRecords(
                    {
                        Table.Max(
                        Table.SelectRows([All Rows], each [Status] <> ""),
                        each [Date]
                        )
                    }
                ),
                each [Record last updated]
            )[Status]
        ),
    #"Added Result" = 
        Table.AddColumn(
            #"Added Status", 
            "Result", 
            each
            Table.Max( 
                Table.FromRecords(
                    {
                        Table.Max(
                        Table.SelectRows([All Rows], each [Result] <> ""),
                        each [Date]
                        )
                    }
                ),
                each [Record last updated]
            )[Result]
        ),
    #"Removed Other Columns" = Table.SelectColumns(#"Added Result",{"ID", "Status", "Result"})
in
    #"Removed Other Columns"