Excel vba - Loop thru a dynamic range, Find value does not go beyond second found value.

Hi,
I have a range of cells in a column which changes with new data.
Code selects the range to last cell in column with value +1.

Some of the cells in the range SUM the totals of the cells above (number of cells vary from 1 to many rows).

Code then finds first cell with "Sum" in formula, offsets to cell on left and inserts formula.
Loops back to do second pass.
That works fine.
Selects next Cell with "Sum" in Formula,offsets to cell on left and inserts formula.
That works fine.
Up to here there is no issue.
From here on though I cannot get the code to move down to the next "Sum" (there may be many) until the last cell in the Range (that was selected in the first place).

Clearly I have a syntax error and some missing code requirement!

Can anyone help?

Here is the code I have so far :

Sub LastCellInColumnOffsetInsert()
        
        Dim foundCount As Long
        Dim RR As Range
        Set RR = Range("I1:I" & Range("I" & Rows.count).End(xlUp).Row)
        RR.Select
    
    Set dynamicRange = Range("I2").CurrentRegion
    For Each cell In RR.Cells
        With RR.Find(What:="sum", _
                    After:=ActiveCell, _
                    LookIn:=xlFormulas, _
                    LookAt:=xlPart, _
                    SearchOrder:=xlByColumns, _
                    SearchDirection:=xlNext, _
                    MatchCase:=False, _
                    SearchFormat:=False).Activate
                 ActiveCell.Offset(0, -1).Select
                    ActiveCell.FormulaR1C1 = "=CONCATENATE(R[-1]C[-7]:R[-1]C[-7],""  "",""TOTAL"")"
     End With
                ActiveCell.Offset(1, 1).Activate
           	 Cells.FindNext.Select
    
    Next
    End Sub