Hello Traore Kalilou,
Welcome to Microsoft Community.
I've read everything you've posted here, as well as the threads in the scheme you refer to.
To your credit, everything you've tried so far is correct and likely to work. But if neither fix the problem, then I might wonder if it's a hardware failure with Typer Cover.
Especially if you've tested Typer Cover in UEFI and noticed that it doesn't work properly in UEFI, it's time to send the device to the Surface support team to check and repair your Surface.
I can direct you to live support who can help you create a repair order:
- Use your personal Microsoft account (not your organization account) to access the following links:
- Type Surface, press Enter, and click "Contact Support" at the bottom:
- Select Technical Support and select the device model you are currently using in Produce family, then click Confrim:
- You will see contact options for Chat support and Phone support, please contact them during working hours to suggest contact:
Finally, please allow me to give a kind reminder. Currently, some users feedback that Chat Support may not be able to contact real-time support, and will encounter errors, so I recommend you to try Phone Support first.
I wish you all the best.
Best Regards,
Mitchell | Microsoft Community Support Specialist