Using Temp Table for ListPart page source table

Hi All
I'm still trying to get tableType = Temporary work in certain scenarios.
Has anyone used a temp table on a listpart page or factbox?
Created a list part page on sales order to show subtotals and the source table is marked as temp table, but then using temp table no data displayed (BC SaaS 19v)

Table

table 60114 SubTotalSales
{
    DataClassification = ToBeClassified;
    Caption = 'sub';
    TableType = Temporary;
    fields
    {
        field(60001; DocNum; Code[50])
        {
            DataClassification = ToBeClassified;
            Caption = 'Code';
        }
        field(60002; Group1; Integer)
        {
            DataClassification = ToBeClassified;
            Caption = 'Code';
        }
        field(60000; Category; Text[200])
        {
            Caption = 'Category;';
        }
        field(60004; SubTotal; Decimal)
        {
            Caption = 'SubTotal';
            Editable = false;
        }
    }
    keys
    {
        key(PK; DocNum, Group1)
        {
            Clustered = true;
        }
    }[img]https://us.v-cdn.net/5022383/uploads/editor/c5/k2mhqygzf5cw.png[/img]

ListPart page - function called from sales order page action

page 50105 SalesSubTotalsPart
{
    PageType = ListPart;
    ApplicationArea = All;
    Editable = false;
    UsageCategory = Administration;
    SourceTable = SubTotalSales;
    DeleteAllowed = false;
    InsertAllowed = false;
    layout
    {
        area(content)
        {
            repeater(Control2)

            {
                Caption = 'Sub';
                ShowCaption = false;
                field(Doc; Rec.DocNum)
                {
                    ApplicationArea = All;
                    Width = 10;

                }
                field(Group1; Rec.Group1)
                {
                    ApplicationArea = all;
                }

                field(Cat; Rec.Category)
                {
                    ApplicationArea = all;
                    Width = 10;
                }

                field(SubTotal; Rec.SubTotal)
                {
                    ApplicationArea = all;
                }

            }
        }
    }

    procedure CalculateSubTotalProc(Var DocNum: Code[50])//called from sales order action

    var
        SalesLine: Record "Sales Line";
      
        TotalAmount: Decimal;

    begin
        Rec.DeleteAll();
        TotalAmount := 0;
        begin//insert
            SalesLine.Reset();

            SalesLine.SetRange("Document Type", SalesLine."Document Type"::Quote);
            SalesLine.SetRange("Document No.", DocNum);
            SalesLine.SetRange(Type, SalesLine.Type::" ");
            if SalesLine.FindSet() then
                Rec.Init();
            repeat
                Rec.DocNum := SalesLine."Document No.";
                Rec.Group1 := SalesLine.Group1;
                Rec.Category := SalesLine.Description;
                Rec.Insert();
            until SalesLine.Next() = 0;
        end;
        begin
            Rec.Reset();
            if Rec.FindSet() then
                repeat
                    Clear(TotalAmount);//
                    SalesLine.Reset();
                    SalesLine.SetRange("Document Type", SalesLine."Document Type"::Quote);
                    SalesLine.SetRange("Document No.", Rec.DocNum);
                    SalesLine.SetRange(Group1, Rec.Group1);
                    if SalesLine.FindSet() then
                        repeat
                            TotalAmount := TotalAmount + SalesLine."Line Amount";

                        until SalesLine.Next() = 0;
                    Rec.SubTotal := TotalAmount;
                    Rec.Modify();

                until Rec.Next() = 0;
        end;

    end;