My macro runs on hidden sheets (and it shouldn't)

To omit hidden sheets you need to tell the code to do such. Also, make sure your sheet references are what you want. Each range should have a proper sheet reference in your scenario.

For csht = 1 To ActiveWorkbook.Sheets.Count 'worksheet or sheets
    If Sheets(csht).Visible = xlSheetVisible Then 'will only apply to visible sheets
        With ActiveSheet
            lastRow = .Cells(.Rows.Count, "A").End(xlUp).Row
        End With
    
        For teller = 11 To lastRow
            'print no of worksheets
            Cells(I + 1, 3) = ActiveWorkbook.Worksheets.Count
            'print sheetname
            Cells(I + 1, 4) = Sheets(csht).Name
            Range(Cells(I + 1, 5), Cells(I + 1, 25)) = Sheets(Sheets(csht).Name).Range("A" & teller & ":Z" & teller).Value
            I = I + 1
        Next teller
    End If
Next csht