deactivate compatibility pop up with excel files

[Krszt]

Hello,

I have a program, that save all xlsx files in xls format. But there is always a pop up that checks the compatibility. How can I skip this pop up with python? I tried to extract it with wb.DisplayAlerts = False and wb.DoNotPromptForConvert = False, but the pop up is still activated.
HEre is the code:

import glob
from win32com.client import Dispatch

for file in glob.glob('C:\Users\iiii\Desktop\python\files\*.xlsx'):
    xl = Dispatch('Excel.Application')
    wb = xl.Workbooks.Add(file)
    wb.SaveAs(file[:-1], FileFormat=56)
    xl.Quit()