I am having similar issues with my SP7 TypeCover. I would never buy this computer if I knew that before.
I have tried everything and the keyboard randomly stops to work. I use it for work and it is extremely frustrating. I have gone back to my previous laptop and will always advocate against Surface line.
Since I do not want to have an over $2000 junk, I will try to get some third-party TypeCover replacement and find a use for it.
Best,
P