Hi,
I have a list, where in one column there are values with "." as decimal delimiter.
All values are formatted as Text.
As I am in Germany and the decimal delimiter of my system is "," so I want to change all these values to numbers with the "," as decimal delimiter.
When I open the file only some of the cells get the warning, that there is a number formatted as text. It seems totally random.

But now I tried several solutions replacing the "." with a "," but in those cells, where I see this Excel warning with the wrong format, all attemps end up with wrong numbers.

Before:
2022-11-30_14-55-57.png

After:
2022-11-30_14-59-27.png

I tried 

Columns("AT:AU").Select
    Selection.Replace What:=".", Replacement:=",", LookAt:=xlPart, _
        SearchOrder:=xlByRows, MatchCase:=True, SearchFormat:=False, _
        ReplaceFormat:=False, FormulaVersion:=xlReplaceFormula2
or 
ActiveSheet.Range("AT:AU").Replace ".", ","
or to change from text to number:
For Each C In ActiveSheet.Range("AT:AU")
      C.FormulaLocal = C.Value
  Next
All of theme result in the same issue, that only these numbers with apparantly wrong format (the ones with the small green arrow in the corner) have then wrong values.
For example the value in the 4th row should be "6,7908" after the change and not "67908".

Can someone point me in the right direction?