Hi EricYL.
Thanks for your reply. I understand that your problem is occurring after the update.In previous replies I have provided you with ways to uninstall the update and use a restore point. Unfortunately they are not effective.
You can try to go back to Windows 10, but please make sure to backup your data.
I do understand your desire to find a 100% safe way to help you get back to Windows 10, but I'm sorry to say that we don't have a 100% safe way to fully help you with your new system and can only avoid data loss by backing up your data.
In addition, before you go back to Windows 10, I suggest you do a fresh install of Windows 11 after backing up your data, and if you still have problems, you try Windows 10 again.
Thank you for your understanding and support.
Best regards,
Zev - MSFT | Microsoft Community Support Specialist