Hello Luminous,
Welcome to Microsoft Q&A.
From your description, it's obvious that you have made a lot of efforts.
However, I need to confirm whether you have reinstalled Windows following the correct process, as Surface is rather special and using a regular USB installation medium is not the right choice. Have you ever referred to the content here: Creating and using a USB recovery drive for Surface - Microsoft Support
Have you ever created a USB recovery drive dedicated to Surface and then used it to restore your Surface to factory Settings? This is the reinstallation step to adapt to the Surface.
If you haven't followed this process before, please follow the video process in the link to complete it all. If your Surface has no hardware malfunctions, this process can usually restore your Surface.
Best Regards,
Kai Ho | Microsoft Q&A Support Specialist