Help grouping rows by consecutive dates and category

There may be more efficient methods but you can do a "double grouping"

• Group by "Person ID", "Role", "Location", "Value"
• For each sub-table
  • Add a custom column that extracts only the Year and Month
  • Create a new table that includes all YrMnths from start to finish
  • Merge the tables
    • nulls will show up where the original table is missing a month from the new table
  • Sort the YrMnth column from the All Dates column (will be Column 1)
  • Group by Person ID using "GroupKind.Local"
    • Then delete the null rows
  • Extract the start and end dates

let
    Source = Table.FromRows(Json.Document(Binary.Decompress(Binary.FromText("nZHBCsIwDIZfRXoeNk1W9QE8KvM+diijyDys0u39sQ7EThSbXBpI8/Glf9tWGVWpSww338+b4xBTCTG1TqF38xDG57XZ2nSS0WA0ApLqKiZHQs5KONCwE/r2bw7/c/DtfeXcek+WL9uTMu7sRnf1vzHDx/CgAWU2EmApk1pmszJb9gN1ajV3H5epqSTEAuIjv0IH8Yh1aoUOy3a8suoe", BinaryEncoding.Base64), Compression.Deflate)), let _t = ((type nullable text) meta [Serialized.Text = true]) in type table [#"Person ID" = _t, Role = _t, Location = _t, Value = _t, Date = _t]),
    #"Changed Type" = Table.TransformColumnTypes(Source,{
        {"Person ID", Int64.Type}, {"Role", type text}, {"Location", type text}, 
        {"Value", type number}, {"Date", type date}}, "en-GB"),
    #"Grouped Rows" = Table.Group(#"Changed Type", {"Person ID", "Role", "Location", "Value"}, {
        {"Consecutives", (t)=>
            let 
                #"YrMnth" = Table.AddColumn(t,"YrMnth", each Date.Year([Date]) * 1000 + Date.Month([Date]),Int64.Type),
                #"All Months" = 
                    Table.FromColumns({
                        List.Numbers(List.Min(#"YrMnth"[YrMnth]), List.Max(#"YrMnth"[YrMnth]) - List.Min(#"YrMnth"[YrMnth])+1)}),
                #"Merge" = Table.Join(#"YrMnth","YrMnth", #"All Months","Column1", JoinKind.RightOuter),
                #"Sort" = Table.Sort(#"Merge",{"Column1", Order.Ascending}),
                #"Remove" = Table.RemoveColumns(#"Sort", {"YrMnth","Column1"}),
                #"Group by Consecutive Dates" = Table.Group(#"Remove", {"Person ID"}, {
                    {"Start Date", each List.Min([Date])},
                    {"End Date", each List.Max([Date])}
                    
                    }, GroupKind.Local),
                #"Remove Null Rows" = Table.SelectRows(#"Group by Consecutive Dates", each [Person ID] <> null)
            in 
                #"Remove Null Rows"}
        }),
    #"Expanded Consecutives" = Table.ExpandTableColumn(#"Grouped Rows", "Consecutives", {"Start Date", "End Date"}),
    #"Changed Type1" = Table.TransformColumnTypes(#"Expanded Consecutives",{{"Start Date", type date}, {"End Date", type date}})
in
    #"Changed Type1"

Results from your posted data